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Telangana TSBIE TS Inter 1st Year Botany Study Material 11th Lesson Cell Cycle And Cell Division Textbook Questions and Answers.

TS Inter 1st Year Botany Study Material 11th Lesson Cell Cycle And Cell Division

Very Short Answer Type Questions

Question 1.
Between a prokaryote and a eukaryote, which cell has a shorter cell division time?
Answer:

1. Prokaryotic cell, has a shorter cell division time due to shorter cell cycle.
2. For instance, bacterial cell cycle is 20 minutes as compared to 90 minutes of cell cycle in yeast.

Question 2.
Among prokaryotes and eukaryotes, which one has a shorter duration of cell cycle?
Answer:

1. Prokaryotes
2. Bacteria (prokaryote) cell cycle is 20 minutes and in human cells (Eukaryote) it is 24 hours.

Question 3.
Which of the phases of cell cycle is of longest duration?
Answer:

1. Interphase
2. In human cell cycle of 24 hours interphase lasts for 23 hours (about 95% of total duration).

Question 4.
Which tissue of animals and plants exhibits meiosis?
Answer:

1. Reproductive tissue – Gamete mother cells.
2. Diploid cells undergo meiosis to produce haploid sex cells.

Question 5.
Given that the average duplication time of E.coli is 20 minutes. How much time will two E.coli cells take to become 32 cells?
Answer:

1. 80 minutes.
2. It takes 4 cell divisions to form 32 cells from initial 2 cells.

Question 6.
Which part of the human body should one use to demonstrate stages in mitosis?
Answer:

1. The cells of the upper layer of epidermis, cells of the lining of the gut and blood cells (bone marrow).
2. The above cells of human body are being constantly replaced.

Question 7.
What attributes does a chromatid require to be classifed as a chromosome?
Answer:
Two chromatids attached at the centromere.

Question 8.
Which of the four chromatids of a bivalent at prophase -1 of meiosis can involve in cross over? [March – 2019]
Answer:

1. Non sister chromatids of the homologous chromosomes (a bivalent).
2. Crossing over occurs of pachytene stage of Prophase -1 in Meiosis.

Question 9.
If a tissue has at a given time 1024 cells, how many cycles of mitosis had the original parental single cell undergone? [Mar. ’20, May & mar. ’14]
Answer:

1. 10 cycles of mitosis.
2. Mitosis is equatorial cell division and doubling of cell number occur per each cell division.

Question 10.
An anther has 1200 pollen grains. How many pollen mother cells must have been there to produce them? [May ’17, Mar. ’17 A.P & T.S ; Mar. ’15 – A.P ; Mar. ’13]
Answer:

1. 300 pollen mother cells.
2. Due to meiosis each PMC produces 4 pollen grains.

Question 11.
At what stage of cell cycle does DNA synthesis occur? [Mar. – 2018]
Answer:

1. S or Synthetic phase of Interphase.
2. During S phase 2C DNA increases to 4C DNA.

Question 12.
It is said that one cycle of cell division in human cells (eukaryotic cells) take 24 hours. Which phase of the cycle, do you think occupies the maximum part of cell cycle?
Answer:

1. Interphase occupies the maximum time i.e., 23 hours.
2. It is about 95% of the total duration of cell cycle is human cells.

Question 13.
It is observed that heart cells do not exhibit cell division. Such cells do not divide further and exit phase to enter an inactive stage called of cell cycle. Fill in the blanks.
Answer:

1. G phase
2. Quiescent stage (G_o)

Question 14.
Identify the substages of prophase – I in Meiosis in which synapsis and desynapsis are formed.
Answer:

1. Synapsis (pairing of homologous chromosomes) occur in zygotene substage of prophase -1 in meiosis.
2. Desynapsis (separation of homologous chromosomes) occur in Diplotene substage of prophase -1 in meiosis.

Question 15.
Name the stage of meiosis in which actual reduction in chromosome number occurs. [Mar. ’15 – T.S]
Answer:

1. Anaphase – I in Meiosis I
2. During this stage homologous chromosome migrate to opposite poles.

Question 16.
Mitochondria and plastids have their own DNA (genetic material). What is their fate during nuclear division like mitosis?
Answer:

1. Mitochondria and plastids have no role during the nuclear division of mitosis.
2. At the time of cytoplasmic division, mitochondria and plastids get distributed between the two daughter cells.

Question 17.
A cell has 32 chromosomes. It undergoes mitotic division. What will be the chromosome number during metaphase? What would be the DNA content (C) during anaphase?
Answer:

1. The chromosome number in the cell at metaphase of mitosis is 32 only. But each chromosome consists of 2 sister chromatids.
2. In anaphase, two sister (daughter) chromatids of a chromosome are separated and move to opposite poles. Each of the separated chromatid consists of 2C DNA.

Question 18.
While examining the mitotic stage in a tissue, one finds some cells with 16 chromosomes and some with 32 chromosomes. What possible reasons could you give to this difference in chromosome number? Do you think cells with 16 chromosomes could have arisen from cells with 32 chromosomes or vice versa?
Answer:

1. In mitosis cells at prophase and metaphase consists of basic sets of chromosomes, i.e., in this case 2m = 16.
2. But at anaphase splitting of two sister (daughter) chromatids of a chromosome leads to doubling of number i.e., 32 that distribute equally (16 each) among two daughter cells formed from a mother cell.

Question 19.
The following events occurs during the various phases of the cell cycle. Fill the blanks with suitable answer against each.
a) Disintigration of nuclear membrane ………………
b) Appearance of nucleolus ………………
c) Division of centromere ………………
d) Replication of DNA ………………
Answer:
a) Prophase
b) Telophase and Interphase.
c) Anaphase
d) S (Synthesis) phase in Interphase.

Question 20.
Two key events take place during s-phase in animal cells – DNA replication and duplication of centriole. In which parts of the cell do thesfe events occur?
Answer:

1. DNA replication occurs in chromosomes present in nucleus during s-phase of Interphase.
2. Centriole duplication occurs in the cytoplasm.

Question 21.
Name a cell that is found arrested in diplotene stage for monthly and years. Comment in two or three sentences, how it completes cell cycle.
Answer:

1. Oocytes of some vertebrates, diplotene can last for months ‘or years.
2. Terminalization of chiasmata occurs in diakinesis and homologous chromosomes separated. Subsequently cell enters into other stages of Meiosis I for reduction of chromosome number.
3. Meiosis II results in formation of 4 daughter cells each with haploid chromosomes set.

Short Answer Questions

Question 1.
In which phase of meiosis are the following formed? Choose the answers from hint points given below.
a) Synaptonemal complex ………………
b) Recombination nodules ………………
c) Appearance / activation of ……………… Enzyme recombinase
d) Termination of chiasmata ………………
e) Interkinesis ………………
f) Formation, of dyad of cells ………………
Hints :
1) Zygotene, 2) Pachytene, 3) Pachytene, 4) Diakinesis, 5) After Telophase – I / Before Meiosis – II, 6) Telophase – I / After Meiosis – I
Answer:
a) Synaptonemal complex Zygotene
b) Recombination nodules Pachytene
c) Appearance / activation of Pachytene Enzyme recombinase
d) Termination of chiasmata Diakinesis
e) Interkinesis After Telophase – I / Before Meiosis – II
f) Formation of dyad of cells Telophase – I / After Meiosis – I

Question 2.
Mitosis results in producing two cells which are similar to each other. What would be the consequence if each of the following irregularities occurs during mitosis?
a) Nuclear membrane fails to disintegrate.
b) Duplication of DNA does not occur.
c) Centromeres do not divide.
d) Cytokinesis does not occur.
Answer:
a) If nuclear membrane fails to disintegrate chromosome cannot spread through the cytoplasm of the cell. Metaphase cannot take place.

b) If Duplication of DNA does not occur equal number of chromosomes cannot enter into daughter cells, results in variable number of chromosomes.

c) If centromeres do not divide chromatid cannot move to opposite poles, then daughter cells have same chromosome number with two chromatids.

d) If cytokinesis does not occur then after cell division each cell contains two nucleus. Resulting multinucleate condition.

Question 3.
Comment on the statement “Meiosis enables the conservation of specific chromosome number of each species even though the process per second, results in reduction of chromosome number.
Answer:

1. Meiosis is the mechanism, by which chromosome number is reduced to half in sexually reproducing organisms.
2. Meiosis produces 4 haploid daughter cells (sex cells or gametes) from a diploid mother cell.
3. Fertilization or union of sex cells again gives rise to diploid (2n) organism.
4. So, Meiosis is the mechanism, by which conservation of specific chromosome number of each species is achieved across generations.
5. It also increases the genetic variability in the population of organisms from one generation to the next, that leads to the evolution.

Question 4.
How does cytokinesis in plant cells differ from that in animal cells?
Answer:

1. Cytokinesis refers to division of a mother cell into 2 daughter cells. This occurs after the Karyokinesis, the division of a mother nucleus into 2 daughter nuclei.
2. In an animal cell, cytokinesis is achieved by the appearance of a furrow in the plasma membrane. The furrow gradually deepens and ultimately joins in the center, dividing the cell cytoplasm into two.
3. Plant cells are enclosed by a relatively in extensible (rigid) cell wall. So in those cells, wall formation starts in the centre of the cell and grows outward to meet the existing lateral walls.

Question 5.
Which division is necessary to maintain constant chromosome number in all body cells of multicellular organism and why? [May. ’14]
Answer:

1. Cell division Meiosis is necessary to maintain constant chromosome number in all body cells of multicellular organisms.
2. The reason is mitosis divide and forms two daughter cells which are similar to parent cell.
3. The chromosome number remains constant in all the cells.
4. Growth occurs due to mitosis.
5. Mitosis also helps in cell repair and growth.

Question 6.
Though redundantly described as a resting phase, interphase does not really involve rest. Comment. [Mar. ’20, ’19, ’18, ’17, ’15, ’13; May ’17]
Answer:

1. In cell cycle, the stage at which the nucleus is not in a state of division is called interphase. It occurs between two successive divisions.
2. During interphase, cell prepares for division by undergoing growth as well as DNA replication in an orderly manner, though considered as resting phase.
3. On the basis of biochemical studies, interphase is subdivided into 3 stages : G₁ phase, S phase and G₂ phase.

G₁ phase :
Cell increases in size. RNA and proteins are synthesised in large quantity.

S phase :
DNA replication occurs and its content increases to 4c from 2c.

G₂ phase :
Synthesis of proteins and RNA is continued. Various cell organelles are newly synthesised. The proteins and energy pools associated with the structure and movement of chromosomes are established.

Long Answer Type Questions

Question 1.
Discuss on the statement – Telophase is reverse of prophase.
Answer:

• The changes occurring in telophase are almost reverse to those which take place in prophase.
• The daughter chromosomes reach opposite poles.
• These daughter chromosomes lengthen and their visibility decreases due to decondensation of chromatin.
• The kinetochore fibres disappear.
• The nuclear membrane reappears.
• Nucleolus, golgi complex and ER reform.
• Thus at the end of telophase, two independent daughter nuclei are organised in the same mother cell.

Question 2.
What are the various stages of meiotic prophase – I? Enumerate the chromosomal events during each stage?
Answer:
Meiotic prophase I is longer and more complex when compared to prophase of mitosis. Prophase I is divided into 5 substages. They are –

1. Leptotene
2. Zygotene
3. Pachytene
4. Diplotene
5. Diakinesis.

1) Leptotene :
Nucleus enlarge in size. Chromosomes are visible. They are long and slender.

2) Zygotene :

1. Homologous chromosomes attract each other and form pairs. These are called bivalents.
2. The process of pairing is called synapsis.
3. Electron micrographs of this stage indicate that chromosome synapsis is accompanied by the formation of complex structure called synaptonemal complex

3) Pachytene :
It is most significant substage of Meiosis I.

1. Each chromosome divides into two chromatids. Thus in each bivalent, 4 chromatids can be seen. These are called pachytene tetrads.
2. In a bivalent, chromatids of the same chromosome are called sister chromatids and those of two different chromosomes are called non-sister chromatids.
3. Pachytene stage is characterised by the appearance of recombination nodules, the sites at which crossing over occurs between non-sister chromatids.
4. The non-sister chromatids exchange their parts mutually at one or two or more places. Such points where the non-sister chromatids physically contact each other are called chiasmata. Chiasmata appear as X – shaped structures.
5. Crossing over is also an enzyme mediated process and the enzyme involved is called recombinase.
6. By the end of pachytene, recombination between homlogous chromosomes is completed leaving the chromosome linked at the side of crossing one.

4) Diplotene :
The beginning of diplotene in recognised by the dissolution of the synaptonemal complex and the tendency of the homologous chromosomes of the bivalent separate from each other except at the site of chaismata.

5) Diakinesis:

1. Chaismata move towards the ends of chromosomes. This is called terminalisation.
2. Bivalents become very thick and short.
3. Nucleolus begins to disappear.
4. Nuclear membrane disappears.
5. Chromosomes are released into cytoplasm.

Question 3.
Differentiate between the events of mitosis and meiosis.
Answer:

Question 4.
Write brief note on the following :
a) Synaptonemal complex
b) Metaphase plate
Answer:
a) Synaptonemal complex :
During the heptotene of prophase I, chromosome start pairing together and this process of association is called synapsis,

1. Such paired chromosomes are called homologous chromosome.
2. Electron micrographs of this stage indicate that chromosome synapsis is accompanied by the formation of complex structure called synoptonemal complex.
3. The complex formed by a pair of homologous synapsed homologous chromosomes is called a bivalent or a tetrad of chromatids.

b) Metaphase plate :
In Metaphase two important changes take place.

1. Formation of bipolar spindle fibres and attach the same to the kinetochores of chromosomes,
2. All the chromosomes lie at the equator.
3. The plane of alignment of the chromosomes at metaphase is referred to as the metaphase plate or equatorial plate.

Question 5.
Write briefly the significance of mitosis and meiosis in multicellular organism.
Answer:
Significance of mitosis :

1. Growth in organism is caused by mitosis and it restores the surface or volume ratio of the cell.
2. The daughter ceils formed by mitosis are identical with the mother cell. Hence it is important in conserving the genetic integrity of the organism.
3. In unicellular organisms, mitosis helps in reproduction.
4. Mitosis helps in wound healing and regeneration of lost plant parts.
5. Mitosis helps for grafting in vegetative reproduction.
6. It maintains a constant number of chromosomes in all the cells of the body.

Significance of meiosis:

1. It helps in the maintenance of a constant chromosome number from one generation to the next.
2. Due to crossing over, genetic recombinations are caused which help in genetic variation and origin of new species and leads to evolution.

Intext Question Answers

Question 1.
Name a stain commonly used to colour chromosome.
Answer:
Acetocarmine

Question 2.
Name the pathological condition when uncontrolled cell division occurs.
Answer:
Cancer

Question 3.
An organism has two pairs of chromosomes (i.e., chromosome number = 4). Diagrammatically represent the chromosomal arrangement during different phases of meiosis – II.
Answer:

Question 4.
Meiosis has events that lead to both gene recombinations as well as Mendelian recombinations. Discuss.
Answer:
Both chiasmata and crossing over occur between non-sister chromatids. Due to crossing over, genetic recombinations are caused. During Anaphase – I of meiosis – I Mendelian recombination takes place.

Question 5.
Both unicellular and multicellular organisms undergo mitosis. What are the differences, if any, observed between the two processes?
Answer:
In unicellular organisms, a cell divides into two halves by binary fission. Stages like Prophase, Metaphase, Anaphase, and Telophase are present in multicellular organisms. It’s not present in unicellular organisms.

Telangana TSBIE TS Inter 1st Year Botany Study Material 10th Lesson Biomolecules Textbook Questions and Answers.

TS Inter 1st Year Botany Study Material 10th Lesson Biomolecules

Very Short Answer Type Questions

Question 1.
Medicines are either man made (i.e., synthetic) or obtained from living organisms like plants, bacteria, animals etc. and hence the latter are called natural products. Sometimes natural products are chemically altered by man to reduce toxicity or side effects. Write against each of the following whether they were initially obtained as a natural product or as a synthetic chemical. [ Mar. ’20]
a. Penicillin b. Sulfonamide c. Vitamin C d. Growth Hormone
Answer:
a. Penicillin-Natural product
b. Sulfonamide-Synthetic chemical
c. Vitaminc-Natural product
d. Growth Hormone-Natural product

Question 2.
Select an appropriate chemical bond among ester bond, glycosidic bond, peptide bond and hydrogen bond and write against each of the following.
a. Polysaccharide
b. Protein
c. Fat d. Water
Answer:
a. Polysaccharide – Glycosidic bond
b. Protein – Peptide bond
c. Fat – Ester bond
d. Water – Hydrogen bond

Question 3.
Give one example for each of aminoacids, sugars, nucleotides and fatty acids. [Mar. ’13]
Answer:

1. Amino acid – Eg: Glycine
2. Sugars – Eg : Glucose
3. Nucleotide – Eg: Adenylic acid
4. Fatty acids – Eg : Palmitic acid

Question 4.
Explain the Zwitterionic form of an amino acid. [Mar. ’14]
Answer:
1) is a zwitterionic form a neutral form due to equal positive and negative charges.
2) Amino acid contains both acidic (carboxylic acid) and basic (amino group) centres and hence shows both positive and negative charge.

Question 5.
What constituents of DNA are linked by glylosidic bond?
Answer:

1. Nitrogen base and pentose (deoxy ribose) sugar, linked by glylosidic bond.
2. This bond is formed by dehydration.

Question 6.
Glycine and Alanine are different with respect to one substituent on the α – carbon. What are the other common substituent groups?
Answer:

1. – H and – CH₃ are substituent groups respectively in Glycine and Alanine – at α – carbon.
2. Both as them contain – H, – COOH and – NH₂ substituent groups in common.

Question 7.
Starch, Cellulose, Glycogen, Chitin are polysaccharides found among the following. Choose the one appropriate and write against each. [Mar. – 2018 m Mar. 17 – A.P & T.S ; Mar. ’15 – T.S]
a. Cotton fibre ………..
b. Exoskeleton of cockroach ……………
c. Liver ………………
d. Peeled potato …………..
Answer:
a. Cotton fibre – Cellulose
b. Exoskeleton of cockroach – Chitin
c. Liver – Glycogen
d. Peeled potato – Starch

Short Answer Questions

Question 1.
Explain briefly the metabolic basis for ‘living’.
Answer:

1. Metabolic pathways can lead to a more complex structure from a simpler structure. For example, formation of sucrose from water and CO₂ in mesophyll. They are called biosynthetic or anabolic pathways.
2. Some metabolic pathways may lead to a simpler structure from a complex structure. For example, glucose becomes lactic acid in our skeletal muscle. They are called as degradative or catabolic pathways.
3. Anabolic pathways, consume energy. For instance, assembly of a protein from amino acids requires energy input.
4. Catabolic pathways lead to the release of energy. For instance, the glycolytic pathway leading to the formation of lactic acid from glucose and releases energy. It consists of 10 metabolic steps.
5. Living organisms have learned to trap the energy liberated during degradation and store it in the form of chemical bonds. This stored bond is utilized as and when biosynthetic, osmotic and mechanical work is performed.
6. The most important form of energy currency in living systems is the bond energy in a chemical called Adenosine Triphosphate (ATP).

Question 2.
Is rubber a primary metabolite or a secondary metabolite? Write four sentences about rubber.
Answer:

1. Rubber is a secondary metabolite.
2. Metabolic products that do not have identifiable functions in the host organisms are called secondary metabolites.
3. Rubber is produced from latex of Hevea and Ficus elastica.
4. Latex is produced in special type of tissues called laticiferous tissues.
5. Tyres of vehicles are made from volcanization rubber.

Question 3.
Schematically represent primary, secondary and tertiary structures of a hypothetical polymer using protein as an example.
Answer:

Question 4.
Nucleic acid exhibits secondary structure, justify with example. [Mar. ’15 – T.S.]
Answer:

1. Nucleic acid exhibits a wide variety of secondary structures.
2. For example, one of the secondary structures exhibited by DNA is a famous Watson-Crick Model.
3. According to this model, DNA exists as a double helix. The two strands of polynucleotides are anti parallel i.e., run in the opposite direction.
4. The backbone is formed by the sugar – phosphate sugar chain.
5. The nitrogen bases are projected more or less perpendicular to the back bone but face inside. Adenine (A) and Guanine (G) of one strand pairs with Thymine (T) and Cytosine (C) respectively, on the other strand. Each step is represented by a pair.
6. Coiling occurs at an angle of 360°. At each step turn is 36°. One full turn of the helical strand involves 10 base pairs.
7. The length of each turn is 34A.
8. The distance between two steps is 3.4A.
9. This form of DNA with above features is called B – DNA.

Question 5.
Comment on the statement “living state is a non-equilibrium steady-state to be able to perform work.”
Answer:

1. A living organism consists of tens and thousands of chemical compounds called metabolites or biomolecules.
2. Biomolecules are present at concentrations characteristic of each of them. For examples, the blood concentration of glucose in a normal healthy individual to 4.5 to 5.0 mm, while that of hormones would be nanograms / ml.
3. All living organisms exist in a steady state characterized by concentrations of each of these biomolecules, that are in a metabolic flux.
4. Any chemical or physical process moves spontaneously to equilibrium. The steady state is a non-equilibrium state. As per the physics, the systems at equilibrium cannot perform work.
5. Living organisms work continuously, they can not afford to reach equilibrium. Hence the living state is a non-equilibrium steady – state to be able to perform work.
6. Living process is a constant effort to present falling into equilibrium, which is acheived by energy input.
7. Metabolism provides a mechanism for the production of energy. Hence the living state and metabolism are synonymous.
8. Thus, without metabolism there can not be a living state.

Question 6.
Dynamic state of body constituents is a more realistic concept than the fixed concentrations of body constituents at any point of time – Elaborate.
Answer:

1. Living organisms like simple bacterial cell, a protozoan, a plant or an animal contain thousands of organic compounds, the biomolecules.
2. The biomolecules are present in certain concentration, and ore expressed as mols/cell or mols/litre etc.,
3. All the biomolecules have a turn over. It means that they are constantly being changed into some other biomolecules and are also made from some other biomolecules. This breaking and making is through chemical reactions that are called metabolism.
4. Each of the metabolic reactions results in the transformation of biomolecules. For example, removal of CO₂ from amino acids making an amino acid into an amine.
5. Majority of these metabolic reactions do not occur in isolation, but are always linked to some other reactions. It means, metabolites are converted into each other in a series of linked reactions called metabolic pathways.
6. The metabolic pathways are either linear or circular, they may criss – cross each other. Flow of metabolites through the pathway has a definite rate and direction.
7. The metabolite flow is called the dynamic state of body constituents. Interlinked metabolic traffic is very smooth and without a single reported mishap for healthy conditions.
8. Every chemical reaction in a metabolic pathway is a catalysed reaction. There is no uncatalysed metabolic conversion in living systems.
9. Proteins with catalytic power are named as enzymes. They hasten the rate of a given metabolic conversion.

Long Answer Type Questions

Question 1.
What are secondary metabolites? Enlist them indicating their usefulness to man.
Answer:
Metabolic products that do not have identifiable functions in the host organism are called secondary metabolites. Secondary metabolites are alkaloides, flavonoides, rubber, essential oils, antibiotics, coloured pigments, scents, gums, spices etc. Many of these secondary metabolites are useful to man.

1. Pigments – Eg : Carotenoids, Anthocyanins etc.
2. Alkaloids – Eg : Morphine, Codeine etc.
3. Terpenoids – Eg: Monoterpenes, Diterpenes etc.
4. Essential oils – Eg : Lemon, grass oil etc.
5. Toxins – Eg : Abrin, Ricin
6. Drugs – Eg : Vinblastin, Curcumin etc.
7. Polymeric substances – Eg : Rubber, gums, cellulose etc.

Question 2.
What are the processes used to analyse elemental composition, organic constituents and inorganic constituents of living tissue? What are the inferences on the most abundant constituents of living tissue? Support the inferences with appropriate data.
Answer:
To analyse elemental composition, organic constituents and inorganic constituents of living tissue one has to perform chemical analysis.

Analyse Organic Compounds:

1. Take any living tissue (a vegetable or a piece of liver etc) and grind it in trichloro acetic acid (Cl₃C COOH) using a motor and a pestle.
2. We obtain a thick slurry.
3. If we were to strain this slurry through a cheese cloth or cotton, we would obtain two fractions. One is called the filtrate or acid soluble pool and the other is retentate or acid insoluble fraction.
4. To identify a particular compound, one has to use various separation technique and separate an organic compound from the rest.
5. Analytical techniques when applied to the compound gives us the molecular formula and probable structure of the compound.
6. All the carbon compounds that we get from living tissues can be called biomolecules.

Analyse inorganic compounds:

1. One weighs a small amount of a living tissue (say a leaf or liver and this is called wet weight) and dry it.
2. All the water evaporates.
3. The remaining material gives dry weight.
4. Now if the tissue is fully burnt, all the carbon compounds are oxidised to gaseous form and are removed.
5. The remaining is called ash.
6. This ash contains inorganic elements like calcium, magnesium etc.
7. Inorganic elements are also in acid solution fraction.

Elemental analysis:
Elemental analysis gives elemental composition of living tissues in the form of hydrogen, oxygen chlorine, carbon etc.

Analysis of compounds gives an idea of the kind of organic and inorganic compounds.

Question 3.
Nucleic acids exhibit secondary structure. Describe through Watson – Crick Model.
Answer:

1. Nucleic acid exhibits a wide variety of secondary structures.
2. For example, one of the secondary structures exhibited by DNA is a famous Watson-Crick Model.
3. According to this model, DNA exists as a double helix. The two strands of polynucleotides are anti parallel i.e., run in the opposite direction.
4. The backbone is formed by the sugar – phosphate sugar chain.
5. The nitrogen bases are projected more or less perpendicular to the back bone but face inside. Adenine (A) and Guanine (G) of one strand pairs with Thymine (T) and Cytosine (C) respectively, on the other strand. Each step is represented by a pair.
6. Coiling occurs at an angle of 360°. At each step turn is 36°. One full turn of the helical strand involves 10 base pairs.
7. The length of each turn is 34A.
8. The distance between two steps is 3.4A.
9. This form of DNA with above features is called B – DNA.

Question 4.
What is the difference between a nucleotide and nucleoside ? Give two examples of each with their structure.
Answer:

Nucleotide	Nucleoside
1. Nucleotide is made up of nitrogen base sugar and phosphoric acid.	1. Nucleoside is made up of nitrogen base and sugar.
2. Nucleotide of RNA is called ribonucleotide and nucleotide of DNA is called deoxyribo nucleotide.	2. Nucleoside with ribose sugar is called riboside of ribo-nucleoside. Nucleoside with deoxyribose sugar is called deoxyribonucleoside.
3. Example : Adenylic acid, guanylic acid, cytidyolic acid, thymidylic acid, uridylic acid, AMP	3. Example : Adeniosine, guanosine, cytidine, thymidine and uridine

Question 5.
Describe various forms of lipid using a few examples.
Answer:

• Lipids are water insoluble.
• Lipids could be simple fatty acids.
• A fatty acid has a carboxyl group attached to an R-group.
  The R – group could be methyl (-CH₃) or ethyl (- C₂H₅) or higher number of – CH₂ groups (1 carbon to 19 carbons). For example, palmitic acid has 16 carbons including carboxyl carbon.
• Arachidonic acid has 20 carbons including carboxyl carbon.
• Fatty acids could be saturated (without double bond) or unsaturated (with one or more C = C double bonds)
• Simple lipid is glycerol which is trihydroxy propane.
  
• Many lipids have both glycerol and fatty acids. Here the fatty acids are found esterified with glycerol. They are then called monoglycerides, diglycerides and triglycerides.
  
• These are also called fats and oils based on melting point.
• Oils have lower melting point (Eg. Gingely oil) and hence remain as oil in winters.
• Some lipids have phosphorous and a phosphorylated organic compound in them. These are called phospholipids. They are found in cell membrane. One example is Lecithin.
• Some tissues especially the neural tissues have lipids with more complex structures.
• If a phosphate group is also found esterified to the sugar, they are called nucleotides. Example of nucleotides are adenylic acid, thymidylic acid, guanylic acid, uridylic acid and cytidylic acid.

Intext Question Answers

Question 1.
What are macro molecules? Give examples.
Answer:
Macro molecules are large sized biomolecules that have high molecular weight, lower solubility and complex molecular structure. It occurs in collaidal state. Macro molecules are formed by polymerisation of large number of micro molecules. They belong to four classes of organic compounds – carbohydrates, lipids, proteins and nucleic acids.

Question 2.
Illustrate a glycosidic, peptide, and a phospho-diester bond.
Answer:
Glycosidic bond :
In a polysaccharide, the individual monosaccharides are linked by means of glycosidic bond. This bond is formed by dehydration. This bond is formed between two carbon atoms of two adjacent monosaccharides.

Peptide bond :
In a polypeptide or a protein amino acids are linked by peptide bonds. These bonds are formed by the reaction between carbocyl group (- COOH) of one amino acid with the amino group (-NH₂) of the next amino acid, with the elimination of water.

Phospho-diester bond :
In a nucleic acid a phosphate moiecty links the 3′ – carbon of one sugar of one nucleotide to the 5′ carbon of sugar of the succeeding nucleotide. The bond between the phosphate and hydroxyl group of sugar is an ester bond. As there is one such ester bond on either side, it is called phospho-diester bond.
5′ carbon end

Question 3.
What is meant by tertiary structure of proteins?
Answer:
When a long protein chain of secondary structure is folded upon itself like a hollow woolen ball, it give rise to tertiary structure.

Tertiary structure is necessary for many biological activities of protein.

This gives us a 3 – dimension view of a protein.

Question 4.
Find and write down structures of 10 interesting small molecular weight biomolecules. Find if there is any industry which manufactures the compounds by isolation. Find out who are the buyers.
Answer:

Question 5.
Proteins have primary structure. If you are given a method to know which amino acid is at either of the two termini (ends) of a protein, can you connect this information to purify or homogeneity of a protein?
Answer:
The primary sturcture of protein is based on the number type and order of amino acid present in the chain. A protein has a linear structure in which the left end of line represents the first and the right end represents the last amino acid. The number of amino acid in between the two ends determine the purity or homogeneity of proteins.

Question 6.
Find out and make a list of proteins used as therapeutic agents. Find other applications of proteins (Eg : Cosmetics etc.)
Answer:
Proteins used as therapeutic agents are thrombin, fibrinogen, enkephalins, antigens, antibodies, streptokinase, protein tyrosine kinase, diastase, renin, insulin, oxytocin, vasopressin, etc.

Other applications :
Proteins are also used in cosmetics, dairy industries, textile industries, research techniques etc.

Question 7.
Explain the composition of triglyceride.
Answer:
The components of triglyceride are single molecule of glycerol and 3 fatty acids. In glycerol 3 carbon atoms are present along with 30 n groups. Fatty acids consists of long chain hydrocarbon with a carboxylic group at one end. Both of them form ester bond. This bond is saturated when single bonded carbons are present and unsaturated when double bonded carbon atoms are present.

Question 8.
Can you describe what happens when milk is converted into curd or yoghurt, based on your Understanding of proteins?
Answer:
Milk is converted into curd or yughurt due to denaturation of proteins. The configuration of protein is lost. In denaturation disruption of bonds that maintains secondary and tertiary structure leads to the conversion of globular proteins into fibrous proteins. This involves a change in physical, chemical and biological properties of protein molecules.

Question 9.
Can you attempt building models of biomolecules using commercially availalble atomic models (Ball and Stick models)?
Answer:
Yes, models of biomolecules can be prepared using commercially available atomic models. Ball and stick models and space filling models are 3D models which serve to display the structure of chemical products and substances or biomolecules.

With ball and stick models, the centers of the atoms are connected by straight lines which represents covalent bonds. Double and triple bonds are often represented by springs.

The bond angles and bond lengths reflects the actual relationship. While the space occupied by the atoms is either not represented at all or only denoted essentially by the relative sizes of the sphere.

Question 10.
Attempt titrating an amino acid against a weak base and discover the number of dissociating (ionizable) functional groups in the amino acid.
Answer:
The existence of different ionic forms of amino acids can be easily understood by the titration curves. The number of dissociating functional group is one in case of neutral and basic amino acids and two in case of acidic amino acids.

Question 11.
Draw the structure of the amino acid, alanine.
Answer:

Question 12.
What are gums made of? Is Fevicol different?
Answer:
Gums are secondary metabolites. It is made up of compounds present in plant, fungi and microbial cells. Yes, Fevicol is different from gum. It is synthetic resin made by polymerisation manufactured by esterification of organic compounds.

Question 13.
Find out a qualitative test for proteins, fats and oils, amino acids and test any fruit juice, saliva, sweat and urine for them.
Answer:
Biuret test for protein :
The biuret test is a chemical test used for determining the presence of peptide bonds, in a positive test, a copper II ion (Cu²⁺ ion) is reduced to copper I (Cu⁺) which forms a complex with the nitrogen and carbon of peptide bonds in an alkaline solution. A violet colour indicates the presence of protein.

Ninhydrin test for amino acid :
Ninhydrin is a chemical used to detect ammonia or primary and secondary amines. When reacting with these free amines, a deep blue or purple colour known as Ruhemann’s purple is evolved. Most of the amino acids are hydrolyzed and reacted with ninhydrin except proline (a secondary amine).

Solubility test for fats and oils :
A positive solubility test for fats is that the fat dissolves in lighter fluid and not in water. In this test, 5 drops of fat or oi! are added in two test tubes containing 10 drops of lighter fluid and 10 drops of cold water respectively.

Fruit juice :
Fruit juice contains sugar. So it cannot be tested by the above mentioned test.

Saliva :
Saliva contains proteins, mineral salts, amylase etc. So.it can be tested for proteins and amino acids.

Sweat :
Sweat contains NaCl salts.

Urine :
Urine contains proteins. So it can be tested for proteins.

Question 14.
Find out how much cellulose is made by all the plants in the biosphere and compare it with how much of paper is manufactured by man and hence what is the consumption of plant material by man annually. What a loss of vegetation!
Answer:
About 100 billion tonnes of cellulose is prepared per year by the plants of the world. The increase in industrialization increased the use of paper. Due to this reason vegetation is being lost to a great extent.

Question 15.
All life forms exhibit “Unity in diversity” – Give reasons.
Answer:
There is a wide diversity of all living organisms but their chemical composition and metabolic reactions appear to be similar. The most abundant chemical in all life forms in water. Living organisms contain more carbon, hydrogen, and oxygen than animate matter.

Telangana TSBIE TS Inter 1st Year Botany Study Material 9th Lesson The Unit of Life Textbook Questions and Answers.

TS Inter 1st Year Botany Study Material 9th Lesson The Unit of Life

Very Short Answer Type Questions

Question 1.
What is the significance of vacuole in a plant cell? [May ’17]
Answer:

1. In plant cell, vacuole plays an important role in osmoregulation.
2. In some plant cells vacuolar sap contains pigments like anthocyanin, which impart colour to the plant parts.

Question 2.
What does ‘S’ refer in a 70S & and 80S ribosome? [Mar. ’17 – T.S.]
Answer:

1. ‘S’ refers sedimentation coefficient (expressed in Svedburg unit)
2. It is indirectly a measure of density and size.

Question 3.
Mention a single membrane bound organelle which is rich in hydrolytic enzymes. [Mar. ’15 – T.S.]
Answer:

1. Lysosomes.
2. They contain hydrolases capable of digesting carbohydrates, proteins, lipids and nucleic acids.

Question 4.
What are gas vacuoles? State their functions.
Answer:
Gas vacuoles are inclusion bodies in cytoplasm of Blue green, purple and green photosynthetic bacteria. They are filled with air and help the bacteria to float on the surface of water.

Question 5.
What is the function of a polysome?
Answer:

1. In prokaryotes, several ribosomes may attach to single m RNA and form a chain called polysome.
2. The ribosomes of a polysome translate the m RNA into proteins.

Question 6.
What is the feature of a metacentric chromosome? [Mar. – 2018]
Answer:

1. The metacentric chromosome has middle centromere.
2. Hence this chromosome consists of two equal arms.

Question 7.
What is referred to as Satellite Chromosome? [Mar. ’20, ’17]
Answer:

1. Satellite Chromosome: Chromosome with non-staining secondary constriction at a constant location.
2. This gives the appearance of a small fragment called the satellite.

Question 8.
What are microbodies? What do they contain? [May ’14]
Answer:

1. Peroxysomes and glyoxysomes are called microbodies.
2. Glyoxysomes contain the enzymes of glyoxylate cycle which convert stored lipid into carbohydrates. Peroxysomes contain enzymes which convert fatty acids into carbohydrates

Question 9.
What is middle lamella made of? What is its functional significance? [Mar. ’15 – A.P.]
Answer:

1. Middle lamella is made of calcium pectate.
2. It holds or glues the different neighbouring cells together.

Question 10.
What is osmosis?
Answer:

1. Movement of water by diffusion across the membrane is called Osmosis.
2. In this process, water moves from higher concentration to lower concentration across the plasma membrane.

Question 11.
Which part of the bacterial cell is targeted in gram staining?
Answer:

1. Chemical composition of cell envelop.
2. Bacteria that take up gram stain are called Gram positive and that do not are called Gram negative.

Question 12.
Which of the following is not correct? [Mar. ’13]
a) Robert Brown discovered the cell.
b) Schieiden and Schwann formulated the cell theory.
c) Virchow explained that cells are formed from pre-existing cells.
d) A unicellular organism carries out its life activities within a single cell,
Answer:
a) Robert Brown discovered the cell – not correct.

Question 13.
New cells generate from
a) bacterial fermentation
c) pre-existing cells
Answer:
c) Pre-existing cells

Question 14.
Match the following. [Mar. – 2019]
a) Cristae i) Flat membranous sacs in stroma
b) Cisternae ii) Infoldings in mitochondria
c) Thylakoids iii) Disc-shaped sacs in Golgi apparatus
Answer:
a) — ii b) — iii c) — i

Question 15.
Which of the following is correct?
a) Cells of all living organisms have a nucleus.
b) Both animal and plant cells have a well defined cell wall.
c) In prokaryotes, there are no membrane bound organelles.
d) Cells are formed de novo from abiotic materials.
Answer:
a) In prokaryotes, there are no membrane bound organelles – correct.

Short Answer Type Questions

Question 1.
Discuss briefly the role of nucleolus in the cells actively involved in protein synthesis.
Answer:

1. A spherical body present in nuclear matrix, the nucleoplasm is called as , nucleolus (plu. Nucleoli). It is not a membrane bound structure.
2. In some nucleus one or more nucleoli may be presents
3. It is a site for active synthesis of ribosomal RNA.
4. rRNA make cell organelles ribosomes, the sites of protein synthesis, several ribosomes may attach with a mRNA to form a chain, referred to be polyribosomes (polysome.) The ribosomes of a polysome translate the mRNA into proteins.
5. Larger and more numerous nucleoli are present in cells actively carrying out protein synthesis.

Question 2.
Explain the association of carbohydrate to the plasma membrane and its significance.
Answer:

1. The lipid component of the plasma membrane mainly cpnsists of phospho-glycerides.
2. Biochemical investigations clearly revealed that the cell membranes also possess carbohydrates.
3. Carbohydrates present outside the plasma membrane and are attached to extrinsic proteins, integral protein and also hydrophilic (polar) heads of the lipids. They may be glycoproteins or glycolipids.

Question 3.
Comment on the cartwheel structure of centriole.
Answer:

1. Centrosome is an organelle usually containing two cylindrical structures called centrioles.
2. They are surrounded by amorphous pericentriolar materials.
3. Both the centrioles in a centrosome lie perpendicular to each other in which each has an organisation like the cartwheel.
4. They are made up of nine evenly spaced peripheral fibrils of tubulin.
5. Each of the peripheral fibril is a triplet. The adjacent triplets are also linked.
6. The central part of the centriole is also proteinaceous and called the hub, which is connected with tubules of the peripheral triplets by radial spokes made of protein.
7. The centrioles form the basal body of the cilia or flagella, and the spindle fibres that give rise to spindle apparatus during cell division in animal cells.

Question 4.
Briefly describe the cell theory,
Answer:

1. Cell theory was proposed by M.J. Sehleiden, a German botanist and T. Schwann, a British zoologist.
2. The cell theory states that
   a) Cell is the structural unit of all organisms.
   b) Cell is the functional unit of all organisms.
   c) R.Virchow proposed that new cells arise from pre-existing cells (Omnis cellula- e-cellula) or from the parent cell.

Question 5.
Differentiate between Rough Endoplasmic Reticulum (RER) and Smooth Endoplasmic Reticulum (SER). [Mar. 17 -A.P.]
Answer:

Question 6.
Give the biochemical composition of plasma membrane. How are lipid molecules arranged in the membrane?
Answer:
The biochemical composition of plasma membrane is lipids, proteins and carbohydrates. In the membrane lipids are arranged in bilayer. Within the membrane lipids are arranged with the polar (hydrophilic) head towards the outer side. This ensures that the non-polar tail of saturated hydrocarbons is protected from the aqueous environment.

Fluid Mosaic Model was proposed by Singer and Nicolson. It is most widely accepted model. They described the cell membrane as “Protein ice bergs in a sea of lipids”. According to this model lipids are quasi-fluid in nature. This enables lateral movement of proteins within the overall bilayer.

Question 7.
What are plasmids? Describe their role in bacteria.
Answer:

1. Small circular DNA molecules found outside genomic DNA in many Bacteria are called plasmids.
2. The plasmid DNA confers certain unique phenotypic characters such as resistance to antibiotics in bacteria.
3. Plasmid DNA is also useful to monitor bacterial transformation with foreign DNA.

Question 8.
What are histones? What are their functions?
Answer:

1. Basic proteins associated with DNA in eukaryotes are called Histones.
2. A typical nucleosome contains 200 bt of DNA double helix wrapped (2 turns) around a core of histone octamer having 2 copies each of 4 types of histone proteins (H2A, H2B, H3and H4). HI histone molecule lies outside the nucleosome core and seals the 2 turns of DNA by binding at the point where DNA enters and leaves the core.
3. The association between negatively charged DNA and positively charged histones allows for a meaningful DNA packaging inside the nucleus.

Question 9.
What is Cytoskeleton? What functions is it involved in?
Answer:

1. An elaborate network of filamentous proteinaceous structures present in the cytoplasm is collectively referred to as cytoskeleton.
2. Eukaryotic cells contain three major components of cytoskeleton – namely micro filaments, intermediate filaments and microtubules.
3. The cytoskeleton in a cell is involved in many functions such as mechanical support, maintenance of cell shape, cell motility, intracelluar transport, signalling across the cell and karyokinesis (movement of chromosomes during cell division).

Question 10.
What is endomembrane system? What cell organelles are not included in it? Why?
Answer:

1. Each of the membranous organelles is distinct in terms of its structure and function.
2. Many of these membranous organelles are together considered as endomembrane system because their functions are co-ordinated.
3. The endomembrane system includes endoplasmic reticulum (ER), golgi complex, lysosomes and vacuoles.
4. Since the functions of mitochondria, chloroplast and peroxisomes are not co¬ordinated with the above components, these are not considered as part of the endomembrane system.

Question 11.
Distinguish between active transport and passive transport.
Answer:
The molecules that moves across the membrane without any requirement of energy is called passive transport. A few ions or molecules are transported across the membrane through its carrier proteins against their concentration gradient, i.e., from lower to the higher concentration. Such a transport is an energy-dependent process, in which ATP is utilised and it is called active transport. Eg : Na+/K+ pump.

Question 12.
What are mesosomes? What do they help in plasma?
Answer:

1. Plasma membrane infoldings in some bacteria are called mesosomes.
2. These special membranous extensions are in the form of vesicles, tubules and lamellae.
3. Mesosomes help in cell wall formation, DNA replication and its distribution to daughter cells.
4. They also help in respiration, secretion, processes, to increase the surface area of the plasma membrane (helps in absorption of nutrients) and enzymatic content.

Question 13.
What are nucleosomes? What are they made of? [Mar. – 2019, May 17 ; Mar. 14]
Answer:
Chromatin appears as beads on string. The beads are known as nucleosomes. Typical nucleosome contains 200 bp of DNA double helix wrapped (two turns) around a core of histone octamer having two copies of each of four types of histone proteins viz., H2A, H2B, H3 and H4.

Question 14.
How do neutral solutes move across the plasma membrane? Can the polar molecules also move across it in the same way? If not, then how are these transported across the membrane?
Answer:

1. Neutral solutes move across the plasma membrane by means of diffusion along
   the concentration gradient. It moves from higher to lower concentration.
2. No, the polar molecule cannot move across it in the same way.
3. Polar molecules require a carrier protein of the membrane to facilitate their transport across the membrane.
4. Some ions or molecules are transported across the membrane against their concentration gradient, which is an energy dependent process. It is called active transport. In active transport ATP is utilised.

Question 15.
Name two cell-organelles that are double membrane bound. What are the characteristics of these two organelles? State their functions and draw labelled diagrams of both. [Mar. ’14]
Answer:
Chloroplast is the cell organelle which contains chlorophyll pigment.

1. Chloroplasts are double membrane bound structure.
2. If the two membrane, the inner membrane is relatively less permeable.
3. The inner space of chloroplast is filled with a colourless matrix called stroma.
4. Flattened sacs called thylakoid are present in stroma
5. They lakoids are arranged as a pile of coins called grana
   
6. Theylakoids enclose space called lumen
7. Lumen contain pigments

Function:

1. Stroma contains enzymes required for the synthesis of carbohydrate and proteins
2. Chloroplasts are photosyathetic in funciton.

Mitochondria is also called the power houses of cell [Mar. ’15 – A.P.]

1. Mitochondria are double membrane bourd structure.
2. Mitochondria is sausage shae or chlirdroca;
3. Eact mitochondria is a double membrane bound structure with outer and inner membrane.
   Structure of Mitochondrion (Longitudinal Section)
   
4. Outer membrane is smooth. Inner membrane divide the lumen into outer compartment and inner compartment.
5. Inner compartment is filled with matrix.
6. Inner membrane forms a number of infoldings called cristae towards matrix.

Function:

1. Mitochondria are the sites of aerobic respiration. They produce cellular energy in the form of ATP. hence they are called power houses of the cell.
2. Matrix possess single circular DNA molecule, a few RNA molecules, ribosome (70S) required for protein synthesis.

Question 16.
What are the characteristics of a prokaryotic cell? [Mar. – 2018, May ’14]
Answer:

1. Prokaryotic cell organisation is fundamentally similar.
2. Prokaryote shows a wide variety of shapes and functions.
3. All prokaryotic cells have cell wall surrounding the cell membrane.
4. The fluid matrix filling the cell is the cytoplasm.
5. There is no well defined nucleus.
6. The genetic material is basically naked, that means not enveloped by a nuclear membrane.
7. In addition to the genomic DNA (circular DNA), many bacteria have small circular DNA outside the genomic DNA. These smaller DNAs are called plasmids.
8. No organelles like in eukaryotes are found except in ribosomes.
9. A specialized differentiated form of cell membrane called mesosome is the characteristic of prokaryotic cell.
10. It is essentially an infolding of the cell membrane.

Question 17.
Multicellular organisms have division of labour. Explain.
Answer:

1. Multicellular organisms have numerous cells.
2. The cells in multicellular organisms originate by the division of single celled zygote.
3. Newly formed cells are specialised to perform specific function and a division of labour is established between these cells which co-exist in the body.
4. Specialization of cells into tissues, organs and organ system is advantageous for multicellular organisms.
5. Different functions are carried out by different groups of cells in an organism. This is known as division of labour.

Question 18.
Cell is the basic unit of life. Discuss in brief.
Answer:

1. All life begins as a singe cell.
2. Cell is a unit of structure and function. The unicellular organisms complete their entire life cycle as a single cell.
3. In multicellular organisms cells are grouped into tissues, tissues into organs and organs into organ system. So cell is a basic unit of every small or complex organism.
4. Each cell is made up of several organelles just like the one carried by different organ system. Thus all the life activities of an organism are present in miniature form in each and every cell of its body.

Question 19.
What are nuclear pores? State their function.
Answer:
At a number of places, the nuclear envelope is interrupted by minute pores which are formed by the fusion of its two membranes. These are called nuclear pores. A nuclear pore has complex structure.

Function :
The nuclear pores are the passage through which movement of RNA and protein molecules takes place in both directions between the nucleus and the cytoplasm.

Question 20.
Both lysosomes and vacuoles are endomembrane structures, yet they differ in terms of their functions. Comment.
Answer:

1. Both lysosomes and vacuoles are endomembrane structures. Yet they differ in terms of their function because they contain different materials.
2. The isolated lysosomal vesicles have been found to be very rich in almost all types of hydrolytic enzymes such as lipase, protease, carbohydrates. These enzymes are capable of digesting carbohydrate, proteins, lipids and nuclic acids.
3. Vacuoles contain water sap, excretory products etc. In Amoeba, conctratile vacuole is important for excretion. In plants it plays an important role in osmoregulation.
4. Thus though lysosomes and vacuoles are endomembrane, they are not similar in structure and function.

Question 21.
Briefly give the contribution of the following scientists in formulating the cell theory.
a) Rudolf Virchow
b) Schleiden and Schwann
Answer:
a) Rudolf Virchow :
First explained that cells divide and new cells are formed from pre-existing cells (Omnis cellula-e cellula). He modified the hypothesis of Schleiden and Schwann to give the cell theory. Cell theory is

1. All living organisms are composed of cells and products of cells.
2. All cells arise from pre-existing cells.

b) Schleiden and Schwann :
Schleiden, a German botanist, examined a large number of plants and observed that all plants are composed of different kinds of cells which form the tissues of the plant.

Schwann, a British zoologist, studied different types of animal cells and reported that cells had a thin outer layer which is today known as plasma membrane. He also concluded, based on his studies on plant tissue, that the presence of cell wall is a unique character of plant cells.

On the basis of this Schwann proposed the hyothesis that the bodies of animals and plants are composed of cells and products of cells.

Question 22.
Is extra genomic DNA present in prokaryotes and eukaryotes? If Yes, indicate their location in both the types of organisms.
Answer:

1. Yes.
2. In prokaryotes, in addition to the genomic DNA (single chromosome / circular DNA) many bacteria have small circular DNA outside the genomic DNA. These smaller DNAs are called plasmids.
3. In Eukaryotes extra genomic DNA is present in mitochondria and chloroplast. Nucleolus has little amount of DNA.

Question 23.
Structure and function are correctable in living organisms. Can you justify this by taking plasma membrane as an example?
Answer:

1. The structure of plasma membrane is similar in all organisms – ranging from unicellular prokaryotes to multicellular eukaryotes.
2. Plasma membrane in all organisms is made of lipid bilayer. The polar (hydrophilic) heads of lipids are faced towards outside and hydrophilic tails are faced towards inside.
3. The function of plasma membrane as semi permeable membrane is also similar in all living organisms.
4. Neutral solutes and solvents like water move across the plasma membrane passively according to their concentration gradient.
5. Polar molecules like ions move across the plasma membrane with the help of carrier proteins against their concentration gradiant. It is called active transprot.

Long Answer Type Questions

Question 1.
What structural and functional attributes must a cell have to be called a living cell?
Answer:

• The cell which have nucleus is called living cell. It was first observed by Robert Brown.
• The cell in which nucleus is absent is called dead cell.
• The nucleus controls and regulates the function of all the cell organelles. It is therefore, referred to as dynamic centre of the cell or master control of the cell or cell brain.
• Nucleus involves in heriditary.
• Nucleus plays an important role in reproduction in unicellular organisms.
• Cytoplasm is a semi fluid matrix. It occupies the volume of the cell.
• Cytoplasm is the main area of cellular activities in both the plant and animal cell.
• Various chemical reactions occur in it to keep the cell in the living state.

Cell organelles :
The cytoplasm shows several membrane bound structures called cell organelles which perform different functions and keep the cell in a dynamic state. Cell organelles are endoplasmic reticulum (ER), the Golgi complex, lysosomes, mitochondria, plastids, microhadies and vacuoles.

In prokaryotic cell membrane bound cell organelles are absent.

Ribosomes are considered as smallest cell organelle in the cells. Ribosomes are not bounded by a definite unit membrane within the cell; Ribosomes are called protein factories as they are important in protein synthesis.

Question 2.
Eukaryotic cells have organelles which may
a. Not be bound by a membrane
b. Bound by a single membrane
c. Bound by a double membrane
Group the various sub-cellular organelles into these three categories.
Answer:
Eukaryotic cells have organelles which may
a) Not be bound by a membrane are Ribosomes.

b) Bound by a single membrane are lysosomes, vacuoles, microbodies (Peroxysomes and Glyoxysomes)

c) Bound by a double membrane are Endoplasmic reticulu,, Golgi bodies, mitochondria, chloroplast, nucleus.

Question 3.
The genomic content of the nucleus is constant for a given species whereas the extra chromosomal DNA is found to be variable among the members of a population. Explain.
Answer:

1. For a given species the genomic content of the nucleus is constant to maintain specificity and stability.
2. Some bacteria have extra chromosomal DNA called plasmids.
3. They can exist independently in the cytoplasm or may be integrated with the chromosome.
4. The plasmids can render bacteria drug resistance, give them new metabolic pathways and make them pathogenic.
5. The presence of DNA in the chloroplast and mitochondria helps in self duplication.
6. Hence both chloroplast and mitochondria are called semi-autonomous organelles.

Question 4.
Justify the statement. “Mitochondria are power houses of the cell”.
Answer:

1. Mitochondria occur in aii eukaryotic cells.
2. Mitochondria possess double membrane envelope. Two unit membranes are separated by perimitochosidriaf space.
3. Outer membrane is smooth. Inner membrane shows invaginations called cristae. The inner space is filled with fluid matrix.
4. Matrix consists of 70S ribosomes, circular DNA and RNA. The matrix also comprises respiratory enzymes.
5. Many stalked particles present on the surface of cristae are called F0- Fx particles.
6. Krebs cycle of respiration occurs in the matrix and electron transport takes place in cristae.
7. Mitochondria are concerned with cellular respiration. Food materials are oxidised and potential energy is converted into kinetic energy. It is stored in the form of adenosine triphosphate (ATP). So mitochondria are called power houses of the cell.

Question 5.
Is there a species specific or region specific type of plastids? How does one distinguish one from the other?
Answer:
Plastids bear specific pigments, thus imparting specific colours to the part of the plant which possesses them. Based on the type of pigments plastids can be classified into chloroplasts, chromoplasts and leucoplasts.

Chloroplasts :
They contain chlorophyll and carotenoid pigments which are responsible for photosynthesis.

Chromoplasts :
In chromoplasts fat soluble carotenoid pigments like carotene, xanthophylls and others are present. This gives the part of the plant a yellow, orange or red colour.

Leucoplasts :
They are colourless plastids of varied shapes and sizes with stored nutrients.
a) Amyloplasts store carbohydrates (starch) Eg. Potato
b) Elaioplasts store oils and fats
c) Aleutoplasts store proteins.

Question 6.
Write the functions of the following.
a. Centromere
b. Cell wall
c. Smooth ER
d. Golgi Apparatus
e. Centrioles
Answer:
a) Centromere :
Every chrpmosome has centromere. On the sides of centromere disc-shaped structures called kinetochores are present. These are the sites of implementation of the microtubules of spindle fibres. During anaphase (cell division) based on the position of centromere, chromosomes exhibit V, L, J and I shapes during their movement towards opposite poles.

b) Cell wall functions :

1. The cell wall protects the protoplast.
2. It gives a definite shape to the cejls and provides mechanical strength.
3. Cell wall is permeable in nature and allows the substances to pass through.

c) Smooth ER:

1. Smooth ER is the major site for synthesis of lipid.
2. In animal cells, lipid like steroidal hormones are synthesized in SER.

d) Golgi Apparatus functions are:

1. It performs the function of packaging materials to be delivered either to the intra-cellular targets or secreted outside the cell.
2. Number of proteins synthesised by ribosomes are modified in the cisternal of golgi apparatus before they are released.
3. It is an important site of formation of glycoproteins and glycolipids.
4. In plants Golgi complex involves in the synthesis of cell wall materials.
5. It plays an important role in “cell plate formation” during cell division.

e) Centriole function :

1. It forms the basal body of cilia or flagella.
2. It forms spindle fibres that give rise to spindle apparatus during cell division in animal cells.

Question 7.
Are the different types of plastids interchangeable? If yes, give examples where they are getting converted from one type to another.
Answer:

• Yes, plastids are interchangeable.
• During various stages of growth, the plastids change their colour from one type to other.
• For instance, in potato when tubers are exposed to air, leucoplasts convert into chloroplasts.
• In tomato and chillies, the Ovaries contain leucoplasts, which change into chloroplasts after fertilisation and in ripe condition, the chloroplasts are transformed into chromoplasts.
• Chloroplasts can be seen in the petals which are green initially but later become coloured.

Question 8.
Describe the structure of the following with the help of labelled diagrams.
i) Nucleus
ii) Centrosome
Answer:
i) Nucleus:

1. Nucleus was first described by Robert Brown.
2. The nucleus consists of highly extended and elaborate nucleo protein fibres called chromatin, nuclear matrix and spherical bodies called nucleoli.
3. The nuclear envelope, consists of two membranes with a space between called the perinuclear space.
4. Outer membrane is continuous with the endoplasmic reticulum and also bears ribosomes on it.
5. At a number of places the nuclear envelope is interrupted by minute pores, which are formed by the fusion of its two membranes.
6. Nuclear pore establishes a contact between nucleoplasm and cytoplasm.
7. The nuclear matrix or the nucleoplasm contains nucleolus and chromatin.
8. Nucleoli are spherical structures present in the nucleoplasm.
9. The content of nucleolus is continuous with the rest of the nucleoplasm as it is not membrane bound structure.
10. Nucleolus is a site for active ribosomal RNA synthesis. Numerous nucleoli carry out protein synthesis.

ii) Centrosome :

1. Centrosome is an organelle usually containing two cylindrical structures called centrioles.
2. They are surrounded by amorphous pericentricular materials.
3. Both the centrioles in the centrosome lie perpendicular to each other in which each has an organisation like cartwheel.
4. They are made up of nine evenly spaced peripheral fibrils of tubulin.
5. Each of the peripheral fibril is a triplet.
6. The adjacent triplet are also linked.
7. The hub of centriole is connected with tubules of the peripheral triplets by radial spokes made of protein.

Question 9.
What is a centromere? How does the position of centromere form the basis of classification of chromosomes? Support your answer with a diagram showing the position of centromere on different types of chromosomes.
Answer:

1. The region of the chromosome where two chromatids are held together at a point along their length is called primary contriction or centromere.
2. Two disc like structures present on either side of the centromere are known as kinetochores.
3. On the basis of centromere position monocentric chromosomes are 4 types :

1. Metacentric :
Centromere is present in the middle point of the chromosome. Both arms are equal in length. Chromosome appears in V shape during anaphase.

2. Submetacentric :
Centromere is slightly away from the middle point of chromosome and both arms are unequal in length. Chromosome appears in ‘L’ shape during anaphase.

3. Acrocentric :
Centromere is present towards one side. One arm is very long and the other arm is very short. Chromosome appears in ‘J’ shape during anaphase.

4. Telocentric :
Centromere is present at the end of the arm. Only one arm is present. Chromosome appears in T shape during anaphase.

Intext Question Answers

Question 1.
What is a mesosome in a prokaryotic cell? Mention the functions that it performs.
Answer:

1. Plasma membrane is made up of lipids and protein.
2. Mesosome is a special membranous structure which is formed by the extensions of plasma membrane into the cell.
3. These extensions are in the form of vesicles, tubules and lamellae.
4. They help in cell wall formation, DNA replication and its distribution to daughter cells.
5. They also help in respiration, secretion processes to increase the surface area of plasma membrane and enzymatic content.

Question 2.
How do neutral solutes move across the plasma membrane? Can the polar molecules also move across it in the same way? If not, then how are these transported across the membrane?
Answer:

1. Neutral solute may move across the membrane by the process of simple diffusion along the concentration gradient i.e., from higher concentration to lower concentration.
2. Polar molecules require carrier proteins of the membrane to facilitate their transport across the membrane.

In active transport, a few ions or molecules (eg., Na+/ K+ pump) are transported across the membrane by carrier proteins against their concentration gradient (i.e. from lower to higher concentration) with the utilization of ATP.

Question 3.
What are the characteristics of a prokaryotic cell?
Answer:

1. Prokaryotic cell organisation is fundamentally similar.
2. Prokaryote shows a wide variety of shapes and functions.
3. All prokaryotic cells have cell wall surrounding the cell membrane.
4. The fluid matrix filling the cell is the cytoplasm.
5. There is no well defined nucleus.
6. The genetic material is basically naked, that means not enveloped by a nuclear membrane.
7. In addition to the genomic DNA (circular DNA) many bacteria have small circular DNA outside the genomic DNA. These smaller DNAs are called plasmids.
8. No organelles like in eukaryotes are found except in ribosomes.
9. A specialized differentiated form of cell membrane called mesosome is the characteristic of prokaryotic cell.
10. It is essentially an infolding of the cell membrane.

Question 4.
Multicellular organisms have division of labour. Explain.
Answer:

1. Multicellular organisms have numerous cells.
2. The cells in multicellular organisms originate by the division of single celled zygote.
3. Newly formed cells are specialised to perform specific function and a division of labour is established between these cells which co-exist in the body.
4. Specialization of cells into tissues, organs and organ system is advantageous for multicellular organisms.
5. Different functions are carried out by different groups of cells in an organism. This is known as division of labour.

Question 5.
Cell is the basic unit of life. Discuss in brief.
Answer:

1. Cell is a unit of structure and function. The unicellular organisms complete their entire life cycle as a single cell.
2. In multicellular organisms cells are grouped into tissues, tissues into organs and organs into organ system. So cell is a basic unit of every small or complex organism.
3. Each cell is made up of several organelles just like the one carried by different organ system. Thus all the life activities of an organism are present in miniature form in each and every cell of its body.

Question 6.
What are nuclear pores ? State their function.
Answer:
At a number of places the nuclear envelope is interrupted by minute pores which are formed by the fusion of its two membranes. These are called nuclear pores. A nuclear pore has complex structure.

Function :
The nuclear pores are the passage through which movement of RNA and protein molecules takes place in both directions between the nucleus and the cytoplasm.

Question 7.
Both lysosomes and vacuoles are endomembrane structures, yet they differ in terms of their functions. Comment.
Answer:

1. Both lysosomes and vacuoles are endomembrane structures. Yet they differ in terms of their function because they contain different materials.
2. The isolated lysosomal vesicles have been found to be very rich in almost all types of hydrolytic enzymes such as lipase, protease, carbohydrates. These enzymes are capable of digesting carbohydrate, protein^, lipids and nuclic acids.
3. Vacuoles contain water sap, excretory products etc. In Amoeba, conctratile vacuole is important for excretion. In plants it plays an important role in osmoregulation,
4. Thus though lysosomes and vacuoles are endomembrane, they are not similar in structure and function.

Question 8.
What is a centromere? How does the position of centromere form the basis of classification of chromosomes? Support your answer with a diagram showing the position of centromere on different types of chromosomes.
Answer:
1) On the basis of centromere position monocentric chromosomes are 4 types :
1. Metacentric :
Centromere is present in the middle point of the chromosome. Both arms are equal in length. Chromosome appears in V shape during anaphase.

2. Submetacentric :
Centromere is slightly away from the middle point of the chromosome and both arms are unequal in length. Chromosome appears in ‘L’ shape during anaphase.

3. Acrocentric :
Centromere is present towards one side. One arm is very long and the other arm is very short. Chromosome appears in ‘J’ shape during anaphase.

4. Telocentric :
Centromere is present at the end of the arm. Only one arm is present. Chromosome appears in ‘I’ shape during anaphase.

Telangana TSBIE TS Inter 1st Year Botany Study Material 8th Lesson Taxonomy of Angiosperms Textbook Questions and Answers.

TS Inter 1st Year Botany Study Material 8th Lesson Taxonomy of Angiosperms

Very Short Answer Type Questions

Question 1.
What is ‘Omega Taxonomy’? [Mar. – 2019, ’18, ’15, ’13 – AP]
Answer:
Taxonomy based on information from other branches such as Embryology, Cytology, Palynology, Phytochemistry etc., in addition to morphological characters is called Omega Taxonomy.

Question 2.
What is Natural system of plant classification? Name the scientists who followed it. [May 14]
Answer:

1. The system in which plants are grouped on the basis of their natural relationships taking all possible morphological characters into consideration is known as Natural system of classification.
2. de Jussieu, de Candolle and Bentham and Hooker followed it.

Question 3.
Explain the scope and significance of “Numerical Taxonomy”.
Answer:

1. Numerical Taxonomy uses mathematical methods to evaluate observable differences and similarities between taxonomic groups. It is now easily carried out using the computers is based on all observable characters.
2. In this process no. and codes are assigned to all the characters and the data are then processed. Each character is given equal importance and at the same time hundreds of characters can be considered.

Question 4.
What is geocarpy? Name the plant which exhibits this phenomenon. [May 17, Mar. 17 – A.P ; Mar. 15 – T.S]
Answer:
Development of fruit inside the soil is known as geocarpy. Eg: Arachis hypogea (groundnut).

Question 5.
Name the type of pollination mechanism found in members of Fabaceae. [Mar. 14]
Answer:

1. Piston mechanism for cross pollination.
2. It is entomophilous, occurs with the help of insects.

Question 6.
Write the floral formula of solanum plant. [Mar 2020]
Answer:

Question 7.
Give the technical description of ovary in solanum nigrum.
Answer:

1. Bicarpellary, syncarpous, bilocular, superior ovary.
2. Placentata swollen with many ovules on axile placentation. Style Carpels are arranged obliquely at 45°.

Question 8.
Give the technical description of anthers of Allium cepa.
Answer:
Anthers are dithecous, basifixed, introse and dehiscence is longitudinal.

Short Answer Type Questions

Question 1.
Write a brief note on semi technical description of a typical flowering plant. [Mar. – 2019]
Answer:
The plant is described beginning with its habit, habitat, vegetative characters, floral characters followed by fruit. After describing various parts of a plant, a floral diagram and a floral formula are presented.

Floral formula indicates the number of free or united members of corresponding whorl as subscript of the respective symbols. It also shows cohesion and adhesion.

Floral diagram provides information about the no. of parts of a flower, their arrangement and their relation with one another.

Question 2.
Describe the non-essential floral parts of plants belonging to Fabaceae.
Answer:
The non-essential floral parts are calyx and corolla.

Calyx :
Sepals five in number, Gamosepalous (sepals united), valvate aestivation. The odd sepal is anterior in position.

Corolla :
Petals five in number, Polypetalous (Petals are free), descending imbricate aestivation. Corolla is Papilonaceous. The posterior petal is the largest and is called ‘Vexillum or Standard Petal’. The two lateral petals are called ‘Wings or Alae’. The two boat shaped petals beneath the wings on the anterior side are called ‘Keel or Carina’. The keel petals are fused and enclose the essential organs.

Question 3.
Give an account of floral diagram.
Answer:
Floral diagram :
It provides information about the number of parts of a flower, their arrangement and the relation they have with one another. The mother axis represents the posterior side of the flower and is indicated as a dot or a circle at the top of the floral diagram. Successive whorls represent calyx, corolla, androecium and gynoecium. Gynoecium at the centre represents T.S. of ovary. The bract represents the anterior side of the ovary.

Question 4.
Describe the essential floral parts of plants belonging to Liliaceae. [Mar. ’20, 18, 17, 15]
Answer:
The essential floral parts are Androecium and Gynoecium.

Androecium :
Stamens are six, arranged in two whorls of three each. They are free or epiphyllous, anthers are dithecous, basifixed, introrse and dehiscence is longitudinal.

In Allium, the stamens are inserted at the base of the tepals which are also fused at the base.

Gynoecium :
Overy is tricarpellary, syncarpous, superior, trilocular with numerous ovules on axile placentation. The style is terminal and stigma is trifid and capitate. The ovary has septal nectaries, one on each septum.

Question 5.
Write a brief account on the class of Dicotyledanae of Bentham and Hooker’s classification.
Answer:
The class Dicotyledonae are characterised by tap root, reticulate venation, tetramerous or pentamerous flowers and two cotyledons in a seed. On the basis of the number of whorls in the Perianth and the condition of petals, the dicotyledons are divided into three sub-classes namely Polypetalae, Gamopetalae and Monochlamydae. Polypetalae was divided into three series namely 1) Thalamiflorae, 2) Disciflorae and, 3) Calyciflorae, Gamopetalae was divided into three series viz. 1. Inferae 2. Heteromerae and 3. Bicarpellatae. Monochlamydae was divided into eight series.

Question 6.
Explain Floral formula.
Answer:
1. The floral formula is represented by some symbols of floral parts.

2. In the floral formula :
a. Br stands for bracteate; Ebr for ebracteate (Bracts absent)
b. Brl stands for bracteolate; Ebrl for ebracteolate (Bracteoles absent)
c. ⊕ stands for actinomorphic; % for zygomorphic

e. K stands for calyx; C for corolla.
f. A for androecium and G for gynoecium.
g. G stands for superior ovary and \(\overline{\mathrm{G}}\) for inferior ovary and G – for half inferior or half superior.

3. Floral formula also indicates the number of free or united (within brackets) members of the corresponding whorl as subscript of the respective symbol.

4. It also shows cohesion (union among similar members) and adhesion (union between dissimilar members).

Question 7.
Give economic importance of plants belonging to Fabaceae. [May ’17, May 14 ; Mar. ’13]
Answer:
1. Pulses :
Pulses like red gram, black gram, green gram, bengal gram are rich source of proteins.

2. Oil :
Groundnut oil from groundnut (Arachis hypogaea) seeds and soyabean oil from seeds of soyabean (Glycine max) are used in cooking.

3. Vegetables :
Pods of bean (Dolichos), soyabean (Glycine max) are used as vegetables.

4. Fodder :
Many plants are used as fodder (Crotalaria & Phaseolus).

5. Fibres :
from Crotalaria (sun-hemp) is used in making ropes.

6. Medicine :
Seeds of Trigonella (Menthi) are used as condiment and medicine. The leaves are used as vegetables.

7. Commercially & Products :
Commercially important products obtained are viz., blue dye (Indigofera tinctoria), yellow dye (Butea monosperma)

8. Medicine :
Medicine is obtained from Derris indica.

9. Green manure :
Sesbania and Tephrosia are used as green manure.

10. Wood :
Wood from (Pterocarpus santalinus) Red sanders is used for making musical instrument.

Long Answer Type Questions

Question 1.
Describe the characteristics of plants belonging to Fabaceae.
Answer:
Vegetative Characters:
Habit :
Many of them are herbs. Some are shrubs, trees, weak stemmed twinners or tendril climbers.

Root System :
Tap root system having root nodules. These nodules contain symbiotic nitrogen fixing bacteria – Rhizobium.

Stem :
Aerial, prostrate or erect, herbaceous or woody climbers.

Leaves :
Cauline, alternate, stipulate, base pulvinate, petiolate, simple or pinnately compound leaf, venation reticulate.

Floral Characters:

Inflorescence :
Axillary or terminal, raceme.

Flower :
Bracteate, bracteolate or ebracteolate, pedicillate, zygomorphic, complete, bisexual, pentamerous, perigynous cup-shaped thalamus.

Calyx :
Sepals five, gamosepalous, imbricate aestivation, odd sepal anterior.

Corolla :
Petals five, polypetalous, papilionaceous consisting of a large posterior petal (standard or vexillum), two laterals (wings or Alae) two anterior fused petals (keel or Carina) enclosing essential organs, vexillary / descendingly imbricate aestivation.

Androecium :
Stamens 10, usually diadelphous [(9) +1] as in Pisum or monadelphous as in Crotalaria, Arachis, anthers dithecous, introse.

Gynoecium :
Monocarpel I ary, unilocular half superior ovary with many ovules on marginal placentation; Style single, long, terminal; stigma simple.

Pollination :
Protandry in flowers prevent self pollination. But Lathyrus, Pisum are self pollinated. Pollination is entomophily and occurs by Piston mechanism.

Fruit :
Generally legume or pod. In Arachis the pods are indehiscent and geocarpic.

Question 2.
Write about the key characteristics of Solanaceae.
Answer:

1. Mostly plants are herbs.
2. Presence of hairs on the plant
3. Bicollateral vascular bundles in the stem
4. Adnation of petioles and pedicels with the internode
5. Pentamerous, actinomrophic and hypogynous flowers
6. Presence of Persistant calyx
7. Epipetalous stamens
8. Bicarpellary, syncarpous, superior ovary with obliquely placed carpels
9. Presence of false septum in the ovary
10. Swollen axile placentation
11. Fruit is a berry or capsuie
12. Presence of curved embryos

Question 3.
Give an account of the family Liliaceae.
Answer:
Class- Monocotyledonae
Series- Coronariae
Family- Liliaceae

I. Vegetative characters:
1. Habitat and habit :
Mesophytes (Allium, Lilium) and also xerophytes (Asparagus, Ruscus, Aloe)are found in this family. Mostly perennial herbs, shrubs or trees are found in some species of Dracaena, Yucca and Aloe. Few are climbers (Gloriosa, Smilax).

2. Root system :
Adventitious root system. In Asparagus, fasciculated tuberous roots are present,

3. Stem :
Mostly perennial underground stems. It may be a bulb (Allium, Lilium, Scilla), rhizome (Gloriosa), or a corm (Colchicum). Gloriosa and Smilax are tendrillar climbers. Cladophylls are present in Ruscus and Asparagus.

4. Leaf :
The leaves are radical (Allium, Lilium) or cauline (Smilax, Gloriosa). Phyllotaxy is usually alternate (Gloriosa) or whorled (Trillium)Simple, petiolate, stipulate exstipulate, parallel venation (exceptionally reticulate in Smilax). Leaves are succulent in Aloe, Yucca and reduced to scales in Asparagus, Ruscus. Stipules in Smilax and leaf apex in Gloriosa are modified into tendrils. Epiphyllous buds present at leaf apex in Scilla.

II. Floral Characters:
1. Inflorescence :
Simple raceme (Asparagus) or panicle (Aloe) or umbel (Allium). Solitary, terminal (Lilium) or Solitary, axillary (Gloriosa).

2. Flower :
Bracteate, ebracteolate, pedicellate, actinomorphic, complete, bisexual,
homochlamydeous, trimerous, and hypogynous.
A) Perianth :
Tepals 6 in two whorls, polyphyllous (Lilium) or gamophyllous (Aloe), petaloid. Odd tepal of outer whorl is anterior, Valvate aestivation.

B) Androecium :
Stamens 6 in two whorls of 3 each, free or epiphyllous. Anthers are dithecous, introrse, basifixed and dehisce longitudinally.

C) Gynoecium :
Tricarpellary and syncarpous. Ovary is superior and trilocular with several ovules on axile placentation. Style is terminal and stigma is trifid, capitate. The ovary has septal nectaries.

3. Floral formula :

4. Pollination :
Flowers are protandrous (Allium) or protogynous (Colchicum) or Herkogamy (Gloriosa) to prevent self pollination. Cross pollination is by entomophily. Yucca has a symbiotic type of pollination by a specific moth, Pronuba yuccasella.

5. Fruit :
Berry or capsule. Seed is monocotyledonous.

III. Economic Importance :
1. Edible :
Allium cepa (bulb), Asparagus (roots), cloves of Allium sativum as spice.

2. Medicinal plants :
Allium cepa [bulb – bactericidal), Allium sativum (cloves – gastric and heart.)

3. Colchicine :
Colchicum, autumnale [mutagen obtained from corm]

4. Fibre yielding plants :
Leaves of Yucca and Dracaena.

5. Ornamental plants :
Gloriosa, Lilium, Asparagus, Dracaena.

Question 4.
Write the characteristics of plants that are necessary for classification. Describe them in brief.
Answer:
Depending upon flowering plants are divided into Non-flowering plants (cryptogamae) and Flowering plants (phaenerogamae)

Sub kingdom :
Cryptogamae (cryptogams): Cryptogams are flowerless and seedless spore plants. They never bear flowers, fruits and seeds. They reproduce asexually by spores and sexually by gametes.

Basing upon the plant body cryptogams are divided into three divisions.
(a) Thallophyta (b) Bryophyta (c) Pteridophyta.

Division Thallophyta :
These are simplest and most primitive plants. All of them have thallus, which is not differentiated into root, stem and leaves.
Division Thallophyta is divided into Algae & Fungi.

Sub division Algae :
Algae are green, photoautotrophic and usually aquatic thallophytes.

Sub division Fungi :
Fungi are non-green (achlorophyllous) heterotrophic . thallophytes.

Division Bryophyta :
Bryophytes are green, autotrophic, embryophytic, nonvascular cryptogams. They are first land plants. They are the amphibians of plant kingdom.

Division Pteridophyta :
Pteridophytes are green, autotrophic, embryophytic, vascular plants.

Sub kingdom Phanerogamae (Phanerogams) :
These are called flowering plants. They bear flowers or cones for reproduction. These phanerogams have one division Spermatophyta.

Division Spermatophyta :
There spermatophytes are seed plants without or with fruits. It is divide into two 1. Gymnospermae 2. Angiospermae.

Gymnospermae (Gymnosperms) :
These are seed plants without ovary and fruit. Seeds are naked without fruit wall.

Angiospermae (Angiosperms) :
These are seed plants with ovaries and fruits. The seeds are enclosed in the fruit wall (pericarp). These are fruit bearing flowering plants.

Depending upon the number of cotyledon in the seed angiosperms are divided into Dicotyledonae and Monocotyledonae.

Class :
Dicotyledonae (Dicot plants) :
Fruit bear seeds with two cotyledons. Tap root system, leaf with reticulate venation, tetra on pentamerous flowers are present.

Class :
Monocotyledonae (Monocot plants):
Fruit bear seeds with one cotyledons; Fibrous root system; leaf with parallel venation; trimerous flowers are present.

Question 5.
Describe a typical flowering plant in the taxonomic perspective.
Answer:
I. Vegetative characters :
1. Habit –

1. Herb / Shrub / Tree
2. annual/biennial / perennial

2. Habitat- Hydrophyte/Mesophyte/Xerophyte

3. Root – Tap root system / Adventitious root system, special character like root modification

4. Stem –

1. Aerial/ underground / sub – aerial
2. Erect / twiner procumbent / prostrate
3. Herbaceous / woody
4. Special characters and modification

5. Leaf –

1. Cauline / ramal / radical
2. Phyllotaxy – Alternate / opposite / circular.
3. Simple / compound leaf
4. Stipulate / exstipulate
5. Leaf base – adnate / pulvinate
6. Petiolate, sessile
7. Reticulate / parallel venation
8. Any special characters or modification.

II. Floral characters:
1. Inflorescence :

1. Axillary/terminal
2. Racemose / cymose / special type
3. Inflorescence type

2. Flower in general

1. Bracteate /Ebracteate
2. Pedicillate / sessile
3. Bracteolate / ebracteolate
4. Actinomorphic / zygomorphic
5. Complete / incomplete
6. Bisexual / unisexual
7. Pentamerous / tetramerous / trimerous
8. Hypogynous / perigynous / epigynous
9. Dichlamydeous /monochlamydeous
10. Heterochlamydeous / homochlamydeous
11. Cyclic / spiral

3. Perianth:
a) Calyx :

1. No. of sepals
2. United (poly) free (gamo)
3. Aestivation – valvate / twisted / intricate
4. Persistent / deciduous
5. Odd sepal – anterior or posterior

b) Corolla :

1. No. of petals
2. United (poly) / free (gamo)
3. Shape : tubular / ligulate / papilionaceous/ funnel shape.
4. Aestivation – valvate / twisted / imbricate

c) Androecium :

1. No. of stamens – definite / indefinite
2. Arrangement – one whorl / two whorls
3. Free / united (monoadelphous / diadelphous / polyadelphous / syngenicious)
4. Length – didynamous / tetradynamous
5. Epiphyllous/ epipetalpus
6. Extrose / introse
7. Fertile / sterile
8. Anthers : dithecous / monothecous
9. Basifixed / dorsifixed versatile.
10. Dehiscence – longitudinal / transverse / porous

Gynoecium :

1. Mono / bi/ tri / tetra / penta / multicarpellary
2. Carpels – United /free
3. Mono / bi/ tri / tetra / penta / multilocular
4. Superior / half superior / inferior ovary
5. Placentation – Axile / central / basal/ marginal
6. Style – terminal / basal / lateral
7. Stigma – capitate / dumbel shaped / bifid

Fruit :

1. Simple / compound / Aggregate
2. Fruit type

Question 6.
Give an account of Bentham and Hooker’s classification of plants.
Answer:
Bentham and Hooker classification is a natural system of classification. It was published in 3 volumes of Genera Plantarum.

They divided flowering plants into 3 classes – Dicotyledonae, Gymnospermae and Monocotyledonae.

Class :
Dicotyledonae :
1. Tap root system 2. Reticulate venation. 3. Flowers tetramerous or pentamerous 4. Seed has two cotyledons Cl. Dicotyledons is divided into 3 sub classes – polypetalae, Gamopetalae and Monochlamydae.

1. Subclass : Polypetalae :
1. Perianth in two whorls.
2. Petals are free.
Sub cl: Polypetalae is divided into 3 series based on the nature of thalamus.

A. Series Thalamiflorae :
Thalamus is elongated, conical or convex.
It has 5 cohorts.

B. Series Disciflorae :
Thalamus is disc shaped.
It has 4 cohorts.

C. Series Calyciflorae :
Thalamus is cup shaped.
It has 5 cohorts.
Family Fabaeceae belongs to order Rosales.

2. Subclass : Gamopetalae :
1. Perianth in two whorls
2. Petals are united.
3. Stamens are epipetalous.

S. Class :
Gamopetalae is divided into 3 series based on the nature of ovary and merosity of flower

A. Series Inferae :
Ovary is inferior.
It includes 3 cohorts.

B. Series Heteromerae :
Ovary is superior.
Carpels are more than two.
It has 3 cohorts.

C. Series Bicarpellatae :
Ovary is superior.
No. of carpels are two.
It has 4 cohorts.
Family Solanaceae belongs to order Polemoniales.

3. Subclass :
Monochlamydeae :
Perianth is not divisible into calyx and corolla. It has 8 series. No cohorts. Families are directly under series.

Class: Gymnospermae :
Seeds are naked. It is divided into 3 families – Cycadaceae, Coniferae & Gnetaceae.

Class : Monocotyledonae :
1. Adventitious root system, 2. Parallel venation, 3. Trimerous flowers and 4. Seed has one cotyledon. It has 7 series. No cohorts. Families are placed directly under the series.

Thus flowering plants are grouped into 202 natural orders now called as families. Of these 165 natural orders belong to Dicotyledonae. 3 to Gymnosperms and 34 belong to Monocotyledonae.

Question 7.
What is taxonomy? Give a brief account of different types of plant classification.
Answer:
Classification of plants into groups based on their similarities and their relationships is called Taxonomy. It deals with characterization, identification, nomenclature and classification.

On the basis of criteria taken into account, classification systems are 3 types. They are
1. Artificial system of classification :
It is based on one or few comparable characters like morphology or natural habits.
Eg: 1: Classification of plants on the basis of form into herbs, shrubs, trees etc., was done by Theophrastus.
Eg: 2 : Sexual system of Linnaeus.

2. Natural system of classification :
Plants are grouped on the basis of their natural relationship taking into consideration all possible morphological characteristics.
Eg : Classification of de Candolle
Bentham and Hooker system

3. Phylogenetic system of classification :
These systems are proposed after the publication of “Origin of species” and the announcement of the “theory of evolution” by Charles Darwin. Hence they are also called post-Darwinism classifications. They reflect the genetic and evolutionary relationships among the taxa and show them in the form of a phylogenetic tree. Ex : Classification of Engler and Prantl in their “Die Naturlichen Plazenfamilien”. J. Hutchinson in his book “Families of Flowering Plants”. Latest phylogenetic classification is APG (Angiospermic Phylogenetic Group) system.

Other Types:
4. Numerical Taxonomy :
Uses mathematical methods to evaluate observable differences and similarities between taxonomic groups. Numerical taxonomy which is now easily carried out using computers is based on all observable characteristics.

5. Cytotaxonomy :
A branch of taxonomy that uses cytological characters like chromosome number, and structure in solving taxonomic problems.

6. Chemotaxonomy :
A branch of taxonomy that uses phytochemical data to solve the problems of taxonomy.

Telangana TSBIE TS Inter 1st Year Botany Study Material 7th Lesson Sexual Reproduction in Flowering Plants Textbook Questions and Answers.

TS Inter 1st Year Botany Study Material 7th Lesson Sexual Reproduction in Flowering Plants

Very Short Answer Type Questions

Question 1.
Name the component cells of the “egg apparatus” in an embryo sac.
Answer:

1. Three cells grouped together at the micropylar end of an embryosac are called egg apparatus.
2. It consists of an egg cell and two synergids on either side of it.

Question 2.
Name the part of gynoecium that determines the compatible nature of pollen grain.
Answer:
Stigma of gynoecium determines the compatibility of pollen grains and promotes post pollination events that lead to fertilization.

Question 3.
Name the common functions that cotyledons and nucellus perform.
Answer:

1. Both are nutritive in function and stores food materials.
2. Cotyledons in seed provide nourishment for embryo, while nucellus of ovule nourishment for embryosac.

Question 4.
Name the parts of pistil which develop into fruit and seeds.
Answer:

1. Ovary of pistil develops into fruit after fertilization.
2. Ovules in the ovary of pistil transforms into seed during post-fertilization events.

Question 5.
In case of polyembryoxy, if an embryo develops from the synergid and another from the nucellus which is haploid and which is diploid?
Answer:

1. Synergid is a haploid cell present in embryo sac, so it gives haploid (n) embryo.
2. Nucellus is diploid tissue in ovule. So it produces diploid (2n) embryo.

Question 6.
Can an unfertilized, apomictic embryo sac give rise to a diploid embryo? If yes, then how?
Answer:

1. Apomixis is an asexual reproduction that mimics sexual process.
2. In some grasses and Asteraceae members, the diploid egg cell formed without reduction division develops into an embryo without fertilization.

Question 7.
Which are the three cells found in a pollen grain when it is shed at the three celled stage ?
Answer:

1. In about 40% of angiosperms, pollen grains are shed at 3 – celled stage.
2. In that pollen grain one vegetative cell and two male gametes (formed by mitiotic division in generative cell) are present.

Question 8.
What is self incompatibility?
Answer:

1. Self incompatibility (self.sterility) is a genetic mechanism that prevents self pollen from fertilizing the ovules by inhibiting pollen germination or pollen tube growth in the pistil. E.g : Abutilon.
2. This is a mechanism to promote cross pollination and to avoid self fertilization.

Question 9.
Name the type of pollination in self-incompatible plants.
Answer:
Gross pollination.

Question 10.
Draw a diagram of a mature embryo sac and show its 8 – nucleate, 7-celled nature. Show the following parts : antipodals, synergids, egg, central cell, polar nuclei.
Answer:

Question 11.
Which is the triploid tissue in a fertilized ovule? How is the triploid condition achieved?
Answer:

1. Endosperm.
2. One of two male gamete released from pollen tube unites with secondary nucleus (formed by the union of two polar nuclei) to from triploid endosperm.

Question 12.
Are pollination and fertilisation necessary in apomixis? Give reasons.
Answer:

1. No, Apomixis is a form of asexual reproduction seen in some species of
   Asteraceae and grasses. In those plants diploid egg cell is formed without – reduction division and develops into embryo without fertilization.
2. In many citrus and mango varieties, the nucellar cells surrounding the embryo sac start dividing, protrude into the embryosac and develop into the embryos.

Question 13.
How is pollination carried out in water plants?
Answer:
1) Epihydrophily :
Pollen grains reach the stigma of female flowers passively by water currents at the surface of water E.g: Vallisnaria.

2) Hypodrophily :
Pollen grains released inside the water reach the stigma of female flowers submerged in water, pollination occurs under water. E.g : Zoostera.

Question 14.
What is the function of the two male gametes produced by each pollen grain in angiosperms?
Answer:

1. One of the two male gametes released from pollen tube unites with egg cell to form zygote (2x).
2. Second male gamete released from the pollen tube unites with secondary nucleus to form endosperm (3x).

Question 15.
Name the parts of an angiosperm flower in which development of male and female gametophyte take place.
Answer:

1. Male gametophyte develops in the pollen grain that are formed in anthers of androecium.
2. Female gametophyte (embryosac) develops in nucellus of ovules formed in gynoecium (carpels).

Question 16.
What is meant by monosporic development of female gametophyte?
Answer:

1. Monosporic development : Embryo sac develops from a single functional megaspore.
2. Monosporic embryosac is 8 nucleate and 7 celled.

Question 17.
Mention two strategies evolved to prevent self-pollination in flowers.
Answer:
1. Dicliny :
Male and Female flowers : (unisexual flowers) are formed on same plant (Maize-monoecious) or on different plants (papaya-dioecious).

2. Heterostyly :
Styles in flowers of the same species are in different heights (Eg: Primula)

Question 18.
Why do you think the zygote is dormant for some time in a fertilized ovule?
Answer:

1. Zygote divides after formation of certain amount of endosperm (nutritive tissue) from PEN is formed.
2. This is an adaptation to provide assured nutrition to the developing embryo.

Question 19.
If one can induce parthenocarpy through the application of growth substances, which fruits would you select to induce?
Answer:

1. Parthenocarpy refers to the fruit production without fertilization of the ovary. This phenomenon is used for commercial production of seedless fruits.
2. Fleshy fruits (Grapes, Banana) in which seeds are not edible, can be selected for induction of parthenocarpy.

Question 20.
Explain the role of tapetum in the formations of pollen grain wall.
Answer:

1. Tapetum is the inner most layer in anther wall. It nourishes the developing pollen grains.
2. Tapetal cells secrete sporopollenin, a constituent in hard outer layer, (escine) . of pollen grain. Sporopollenin can withstand high temperatures, strong acids and alkali.

Question 21.
What is meant by scutellum? In which type of seeds is it present?
Answer:

1. Cotyledon of monocots (Grass family) is called scutellum.
2. In grass family, scutellum is situated towards one side (lateral) of the embryonal axis.

Question 22.
Define with examples endospermic and non-endospermic seeds.
Answer:

1. Mature seeds of castor and coconut that consists of nutritive tissue for embryo (endosperm) are called endospermic seeds.
2. In seeds of pea, groundnut, beans etc., endosperm may either be completely consumed by the developing embryo, before seed maturation, so they are called non-endospermic seeds.

Short Answer Type Questions

Question 1.
List three strategies that a bisexual chasmogamous flower can evolve to prevent self pollination (autogamy).
Answer:
The three strategies that a bisexual chasmogamous flower can prevent self pollination are
1. Dichogamy :
Androecium and gynoecium of a bisexual flower mature at different times. This mechanism promote cross pollination by preventing self pollination in bisexual flowers. It is of 2 types.

a) Protandry :
Androecium matures earlier than gynoecium. The entire pollen fall off from the stamens, by the time gynoecium matures.
E.g: Helianthus, Gossypium.

b) Protogyny :
Gynoecium matures earlier than androecium. Thus, by the time the gynoecium matures, the stamens remain in immature condition.
E.g: Solanum, Scrophularia.

2. Herkogamy :
The arrangement of male and female reproductive organs at different levels in a bisexual flower. This contrivancy prevents self pollination, though both the reproductive organs mature at the same time.
E.g : (a) Stigmas project beyond stamens in Hibiscus, (b) Stigmas bend in opposite direction to stamens in Gloriosa superba.

3. Self sterility :
In some bisexual flowers, the pollen grains fail to germinate on the stigma of the same flower. But the same pollen grains germinate, when they fall on the stigma of other flowers of the same species.
E.g: Abutilon, Passiflora

Question 2.
Given below are the events that are observed in an artificial hybridization programme. Arrange them in the correct sequential order in which they are followed in the hybridization programme.
a) Rebagging b) Selection of parents c) Bagging d) Dusting the pollen on stigma e) Emasculation f) Collection of pollen from male.
Answer:
i) Selection of parents.
ii) Emasculation
iii) Bagging
iv) Collection of pollen from male
v) Dusting the pollen on stigma
vi) Rebagging

Question 3.
Vivipary automatically limits the number of offsprings in a litter. How?
Answer:

1. The plants which grow in Marshy places are called Mangrooves.
2. These plants show Vivipary.
3. Vivipary seeds germinate while they are still attached to the mother plant.
4. Seeds when fall on Marshy places can not germinate because of high salinity and more water conditions. In these plants, seeds germinate when they are in mother plant.

So Vivipary automatically limits the number of offsprings in a litter.

Question 4.
Does self incompatibility impose any restrictions on autogamy? Give reasons and suggest the method of pollination in such plants.
Answer:

1. Yes, self incompatibility impose restrictions on autogamy.
2. The reason is this is a genetic mechanism. When the pollen grain falls on the stigma of the same flower it will not germinate. But when the same pollen grain falls on other flower it will germinate.
3. The method of pollination in such plants will be only cross-pollination.

Question 5.
What is polyembryony and how can it be commercially exploited?
Answer:

1. Development of more than one embryo in the same seed is called polyembryony.
2. It is helpful in developing new varieties such as citrus and mango.
3. The plantlets obtained from these embryos are virus free and has more vigour.
4. Nucellar polyembryony is of great significance in horticulture. These embryos provide uniform seedlings of the parent type as obtained through vegetative propagation.

Question 6.
Are parthenocarpy and apomixis different phenomena? Discuss their benefits.
Answer:
Yes, parthenocarpy and apomixis are different phenomena.

Parthenocarpy :
The fruit production without fertilization of the ovary is called parthenocarpy. This phenomenon is applied for the commercial production of seedless fruits. E.g.: Banana, Grapes. This is more useful to juice industries.

Apomixis :
The seed production without fertilization is called apomixis. Production of hybrid seeds is costly and hence the cost of hybrid seeds becomes too expensive for the farmers. If these hybrids are made into apomicts, there is no segregation of characters in the hybrid progeny. Then the farmer can keep on using the hybrid seeds to raise crop year after year and he does not have to buy hybrid seeds every year.

Question 7.
Why does the zygote begin to divide only after the division of Primary endosperm cell (PEC)?
Answer:

1. Primary endosperm cell (PEC) divides repeatedly to form endosperm.
2. Endosperm is nutritive tissue.
3. Zygote divides only after certain amount of endosperm is formed.
4. This is an adaptation to provide assured nutrition to the developing embryo.

Question 8.
The generative cell of two-celled pollen divides in the pollen tube but not in a three-celled pollen. Give reasons.
Answer:
In over 60 per cent of angiosperms, the pollen grains are shed at two celled stage. They are vegetative cell and generative cell. After pollination, during germination, in the pollen tube the generative cell divides to give rise to two male gametes.

In the remaining 40 per cent of angiosperms, the pollen grains are shed at three celled stage. The reason is the generative cell divides to give rise to two male gametes before pollination.

Question 9.
Discuss various types of pollen tube entry into ovary with the help of diagrams.
Answer:
Entry of pollen tube into the ovule : It is of 3 types.

1. Porogamy :
The pollen tube enters into the ovule through the micropyle. It is the most common type in many plants. E.g : Ottelia, Hibiscus

2. Chalazogamy :
The pollen tube enters into the ovule through chalaza. It was discovered by Treub in Casuarina.

3. Mesogamy :
The pollen tube enters the ovule through funiculus or integuments. E.g: Cucurbita

Question 10.
Differentiate between microsporogenesis and megasporogenesis. Which type of cell division occurs during these events? Name the structures formed at the end of these two events.
Answer:

1. Microsporogenesis is a process in which diploid microspore mother cells divide meiotically to form microspores.
2. Megasporogenesis is a process in which diploid megaspore mother cell divides meiotically to form megaspores.
3. Meiosis occurs during these events.
4. Microspores and megaspores are formed at the end of these two events.

Question 11.
What is bagging technique? How is it useful in a plant breeding programme?
Answer:
Emasculated flowers are covered with a bag of suitable size. Generally made up of butter paper. This is called bagging. This is useful to prevent contamination of its stigma with unwanted pollen.

Question 12.
What is triple fusion? Where and how does it take place? Name the nuclei involved in triple fusion.
Answer:

1. The second male gamete fuses with the secondary nucleus (formed by the fusion of two polar nuclei) of the embryo sac. This results in the formation of a triploid Primary endosperm nucleus (PEN). As this invovles the fusion of three haploid nuclei, it is termed triple fusion.
2. Triple fusion occurs within the female gametophyte (embryo sac) of ovules.
3. Nuclei involved in triple fusion are two polar nuclei of central cell and nuclei of male gamete.

Question 13.
Differentiate between
a) Hypocotyl and Epicotyl
b) Coleoptile and Coleorhiza
c) Integument and Testa
d) Perisperm and Pericarp
Answer:

Question 14.
What is meant by emasculation? When and why does a plant breeder employ this technique?
Answer:
Removal of anthers from the bisexual flower bud before the anther dehisces is called emasculation. It is done by forceps during bud condition. This prevents contamination of its stigma with unwanted pollen.

Question 15.
What is apomixis? What is its importance?
Answer:

1. Production of seeds without fertilisation is called apomixis. It is a form of asexual reproduction.
2. Apomixis do not involve Meiosis. Hence seggregation and recombination of chromosomes do not occur. Thus Apomixis help in preserving desirable characters for indefinite periods.
3. Production for hybrid is costly. If these hybrids are made into apomixis, then the farmer can raise new crop year after year and he does not have to buy hybrid seeds every year.

Long Answer Type Questions

Question 1.
Starting with the zygote, draw the diagrams of the different stages of embryo development in a dicot.
Answer:

Question 2.
What are the possible types of pollinations in chasmogamous flowers? Give reasons.
Answer:
The flowers which open are called chasmogamous flowers. In these flowers self pollination or cross pollination may take place.

Self pollination –
The transfer of pollen grain from anther to stigma of same flower is called self pollination. The reason is the male reproductive organ (stamen) and female reproductive organs (carpels) mature at the same time. They lie side by side. This assures self pollination.

Cross pollination :
The transfer of pollen grain from anther to stigma of another flower is called cross pollination. It is 2 types.

i) Geitonogamy :
Cross pollination between two flowers of same plant is called geitonogamy. In this, there is no genetic variation, eg: Coeds nucifera (coconut)

ii) Xenogamy :
Cross pollination between two flowers of different plants belonging to the same species is called xenogamy. Eg : Borassus.

Continued self pollination results in inbreeding depression. So flowering plants have developed many devices or adoptations or contrivances to discourage self – pollination and encourage cross pollination.

Question 3.
With a neat, labeled diagram, describe the parts of a mature angiosperm embryo sac. Mention the role of synergids. [March 2019, ’17, ’14, May ’17]
Answer:

In angiosperms female gametophyte is called embryo sac. Embryo sac consists of three parts i.e. Egg apparatus, Antipodals and Central cell.

Egg Apparatus :
The three cells towards the anterior side are together called Egg apparatus. The middle big cell is called egg cell which acts as a female gamete. The two cells present on either side of the egg cell are called synergids.

Role of Synergids :
Synergids contain finger like projections called filiform apparatus, which help in absorption and conduction of food materials from nucleus into the embryo sac. They also help in directing the movement of pollen tube towards the embryo sac.

Antipodals :
The three cells present towards posterior side are called antipodals.

Central cell :
Central cell is the largest cell with central vacuole and two polar nuclei.

Question 4.
Draw the diagram of a microsporangium and label its wall layers. Write briefly about the well layers. [Mar. – 2020. 2018, May ’14]
Answer:

Anther wall consists of

1. One cell thick outer protective layer, epidermis. The thin walled epidermal cells between two pollen sacs constitute stomium, which is useful for the dehiscence of pollen sacs.
2. Endothecium, a layer of radially expanded cells present below the epidermis. These cells have hygroscopic fibrous thickenings of cellulose and help in the dehiscence of pollen sac.
3. Middle layers present below the endothecium consists of 1 – 5 layers of thin walled cells.
4. Tapetum is the innermost nutritive layer of anther wall, which encircles the sporogenous tissue. The cells in this layer are large, thin walled, bi – or multinucleate and nourish the developing sporogenous tissue.

Question 5.
Embryo sacs of some apomictic species appear normal but contain diploid cells. Suggest a suitable explanation for the condition.
Answer:

1. Apomixis is a form of asexual reproduction that mimics sexual reproduction.
2. In this method seeds are produced without fertilization.
3. A few flowering plants such as some species of asteraceae and grasses have evolved a special mechanism to produce seeds through apomixis.
4. In some species, the diploid egg cells is formed without reduction division. It develops into the embryo without fertilization.
5. Apomictic method is an assured reproduction in the absence of pollinators, such as in extreme environments.
6. Seeds produced by apomixis can be called as clones, because they are resulted from mitotic cell divisions and resemble the parent and also one another in all characters.
7. In many citrus and mango varieties, some of the nucellar cells surrounding the embryo sac start dividing, protruds into the embryo sac and develop into the embryos. In such species each ovule contains many embryos. Occurrence of more than one embryo in a seed is referred to as polyembryony.
8. Hybrid varieties of several of our food and vegetable crops are being extensively cultivated. This led to tremendous increase in productivity. But hybrid seeds are to produced every year, the progeny from hybridization may segregate and do not maintain characters. If the hybrids are made into apomictics, the farmer does not have to buy hybrid seeds every year.
9. Because of the importance of apomixis in hybrid seed in dusty, active research is going on in many laboratories around the world to understand the genetics of apomixis and to transfer apomictic gene into hybrid varieties.

Question 6.
Describe the process of fertilisation in angiosperms.
Answer:
Fertilization :

1. The fusion of male and female gametes is called fertilization.
2. In angiosperms, female gamete is an egg cell and is present in embryo sac (female gametophyte).
3. Embryo sac is embedded in the ovule which is present inside the ovary of gynoecium.
4. Male gametophyte (pollen grain) produced in the anther reaches the stigma by pollination at 2 – celled stage.
5. It germinates on the stigma and produces pollen tube, which grows into the style and reaches the ovule.
6. In the pollen tube generative cell divides and produces two male gametes.

I. Entry of pollen tube into the ovule: It is of three types.
1. Porogamy :
The pollen tube enters into the ovule through the micropyle. It is the most common type in many plants. E.g: Ottelia, Hibiscus.

2. Chalazogamy :
The pollen tube enters into the ovule through chalaza. It was discovered by Treub in Casuarina.

3. Mesogamy :
The pollen tube enters the ovule through funiculus or integuments. E.g: Cucurbita.

II. Entry of pollen tube into Embryo sac:
After the entry of pollen tube into the ovule, it enters into the embryo sac only through the micropylar region, either passing in between egg cell and , synergid or penetrating through synergid cell. The entry of pollen is directed by filiform apparatus.

III. Discharge of male gametes (sperms)into embryo sac :
The male gametes are released into the embryo sac by (a) bursting of pollen tube tip or f b) degeneration of the tip or (c) by the formation of an apical pore. The pollen tube finally releases the intact male gametes (cells) and vegetative nucleus.

IV. Gametic fusion :
According to many scientists, only the nuclei of male gametes migate out of them. But recent evidences suggest that the male cytoplasm is also involved in fertilization.

V. Triple fusion and Double Fertilization :
Syngamy :
One (first) of the sperm fuses with the egg cell and forms a diploid zygote. This fusion is called Syngamy or fertilization and was first discovered by Strasburger (1884). This is also called True or real fertilization.

Triple fusion :
The second sperm nucleus fuses with the secondary nucleus (formed by the fusion of two polar nuclei) of the embryo sac. This results in the formation of a tripioid primary endosperm nucleus (PEN). Hence it is called Triple fusion. It was discovered by Nawaschin in Lilium and Fritillaria. This is also called vegetative fertilization.

Double Fertilization :
In angiosperms, two male gametes released from the pollen tube take part in two fertilizations (Syngamy and Triple fusion). So, this phenomenon is called Double Fertilization.

Telangana TSBIE TS Inter 1st Year Botany Study Material 6th Lesson Modes of Reproduction Textbook Questions and Answers.

TS Inter 1st Year Botany Study Material 6th Lesson Modes of Reproduction

Very Short Answer Type Questions

Question 1.
What is the dominant phase in the life cycle of an angiosperm?
Answer:

1. Multicellular diploid sporophytic stage is the dominant phase in the life cycle of an angiosperm.
2. Sporophyte produces haploid spores via meiosis and a few called gametophytes.

Question 2.
What is meant by heterospory? Mention the two types of spores developed in an angiospermic plant?
Answer:

1. Heterospory : A condition in which a plant produces two types of spores.
2. They are microspores (Pollen grains) and megaspores (embryosac mother cells).

Question 3.
Mention the modes of reproductive in Algae and Fungi.
Answer:

1. Algae (Chlamydomonas) reproduce asexually by motile zoospores, vegetatively by fragmentation and sexually by motile gametes.
2. Fungi (Rhizopus) reproduce asexually by non-motile spores and conidia, vegetatively by fragmentation and sexually by gametes.

Question 4.
How do Liverworts reproduce vegetatively?
Answer:

1. Liverworts reproduce vegetatively by specialised structure called gemmae.
2. They also show vegetative reproduction via. fragmentation.

Question 5.
Mention any two characteristics of bacteria and yeast that enable them to reproduce asexually.
Answer:

1. Both bacteria and yeast are single celled organisms, in which cell division itself is asexual reproduction.
2. Bacteria reproduce by binary fission, while yeast reproduce by budding.

Question 6.
Why do we refer to offspring formed by asexual method of reproduction as clones?
Answer:

1. Offspring formed by asexual vegetative method and that do not involve two parents are called clones.
2. Clones of a plant are morphologically and genetically identical.

Question 7.
Between an annual and a perennial plant, which one has a shorter juvenile phase ? Give one reason.
Answer:

1. Annual plant has a shorter juvenile or vegetative phase.
2. Annuals like maize, wheat and rice have vegetative phase less than a year and that ends after flowering.

Question 8.
Rearrange the following events of sexual reproduction in the sequence in which they occur in a flowering plant: embryogenesis, fertilisation, gametogenesis, pollination.
Answer:
Pollination Gametogenesis Fertilisation Embryogenesis.

Question 9.
Is there a relationship between the size of an organism and its life span?
Answer:

1. There is no absolute relationship between life span and size of an organism.
2. Osmunda (Royal fern), a herbaceous plant lives for 100 + years. In general, plants that complete the life cycle (Wolffia) in short time are smaller as compared to plants, with long life span.

Question 10.
Give reasons as to why cell division can or cannot be a type of reproduction in multicellular organisms.
Answer:

1. In muiiicelluiar organisms, often cell division (mitosis) leads to growth .
2. But cell division (meiosis) in sex organs is responsible for reproduction via gamete formation.

Question 11.
Which of the following are monoecious and dioecious organisms?
a) Date palm b) Coconut c) Chara d) Marchantia
Answer:
a) Date palm – Dioecious
b) Coconut – Monoecious
c) Chara – Monoecious
d) Marchantia – Dioecious

Question 12.
Match the following given in column A with the vegetative propagules given in column B.

Answer:
i) c ii) f iii) b iv) a v) d vi) e

Question 13.
What do the following parts of a flower develop into after fertilisation?
a) Ovary b) Stamens c) Ovules d) Calyx
Answer:
a) Ovary – fruit
b) Stamens – drops away
c) Ovule – seed
d) Calyx – withers away or drops away

Question 14.
Define vivipary with an example.
Answer:

1. Vivipary of germination of seeds inside the fruit while still attached to the parent plant.
2. In mangrove plants like Rhizophore, it is a strategy to lower the environmental stess and ensuring successful establishment of plantlet.

Short Answer Type Questions

Question 1.
In haploid organisms that undergo sexual reproduction. Name the stage in the life cycle where meiosis occurs. Give reasons for your answer.
Answer:

1. Heploid organisms like chlamydomonas, chara etc., produce gametes (naploid) by mitotic division that fuse to form diploid zygote.
2. In any haploid organism meiosis occurs after fertilization, in diploid cell.
3. Meiotic division is meant for conservation of specific chromosome number of each species.
4. In Fungi, Algae and Bryophytes having haploid plant body and haplontic life cycle meiosis occurs in zygote to restore the haploid chromosome number and to continue the life cycle.

Question 2.
The number of taxa exhibiting asexual reproduction is drastically reduced in higher plants (angiosperms) when compared to the lower groups of plants. Analyse the possible reasons to this situation.
Answer:

1. In multicellular or colonial forms of algae, moulds and mushrooms vegetative reproduction by fragmentation is prime method of reproduction,
2. Few taxa of angiosperms produce negetative propagules like runness, stolons, suckers etc., and most of species shifted to sexual reproduction.
3. Vegetative reproduction does not involve two parents, formation of gametes and fertilization.
4. Even the algae and fungi shift to sexual method of reproduction just before the onset of adverse conditions. In general, zygote formed by sexual reproduction is thick walled, resistant to dessication and damage.
5. Further sexual reproduction brings about genetic recombination and variation. So, angiospermings have sexual mode of reproduction predominantly.

Question 3.
Is it possible to consider vegetative propagation’observed in plants like Bryophyllum, water hyacinth and ginger as a type of asexual reproduction? Give two / three reasons.
Answer:
a) Yes, reproductive leaves in Bryophyllurrt, offsets in water hyacinth and rhizome in ginger are vegetative propagules.

In asexual reproduction, a single individual (parent) is capable of producing offspring. Hence, the offspring produced are identical to each other and are also exact copies (clones) of their parent.

b) In production of vegetative propagules, there is no involvement of two parents, formation of gamete and fertilization.

Question 4.
“Fertilisation is not an obligatory event for fruit production in certain plants.” Explain the statement.
Answer:
In some plants parthenocarpy is observed. Parthenocarpy means development of fruits without fertilisation. They are seedless. The development of an embryo from unfertilised egg cell is known as parthenogenesis. It is a form of asexual reproduction. Hence fertilisation is not an obligatory event for fruit production in certain plants. Eg : Guava, pineapple etc.

Question 5.
List the changes observed in angiosperm flower subsequent to pollination and fertilisation. [Mar. ’17 – A.P. : Mar. ’14, ’13]
Answer:
Changes taking place in the angiospermic flower after fertilization are called post-fertilization changes.

1. Sepals, petals, stamens, styles and stigma fall off.
2. After fertilization ovary develops into fruit. It stores food materials.
3. Fertilized ovules develop into seeds.
4. Zygote changes into – Embryo
5. Synergids & Antipodals – Degenerate
6. Primary endosperm nucleus forms – Endosperm

Question 6.
Suggest a possible explanation why the seeds in pea pod are arranged in a row, whereas those in tomato are scattered in the juicy pulp.
Answer:

1. Seeds develop from ovules after post-fertilization changes, while dry transforms into fruit.
2. In pea plant, there is marginal placentation. Ovules are borne on a ridge (placenta) along the yentral suture of the ovary. Hence, seeds are present in row in pea pod.
3. In tomato, pariental placentation is present, the ovules develop on the inner wall of the ovary or on peripheral part. So seeds are scattered in juicy pulp formed from mesocarp and endocarp.

Question 7.
Justify the statement ‘Vegetative reproduction is also a type of asexual reproduction’. [May ’17]
Answer:

1. Reproduction not involving the fusion of male and female gametes is called asexual reproduction.
2. In Algae, moulds and mushrooms, the plant body break into smaller portions (fragmentation) and each fragment thing is formed and develops into a mature plant. Gemmae of liver worts are also vegetative reproductive structures.
3. In flowering plants runner, stolon, sucker, offset rhizome, corm, tuber, bulb, bulbil, reproductive leaves are also vegetative propagules.
4. In vegetative reproduction, there is no involvement of two parents, male and female gametes are not formed and are not fused. Offspring produced vegetatively by a plant are identical to one another and are exact copies (clones) of their parent.
5. Hence, vegetative reproduction is also a type of asexual reproduction.

Question 8.
Define (a) Juvenile phase. (b) Reproductive phase. [Mar. – 2020]
Answer:
(a) Juvenile Phase :
All organisms have to reach a certain stage of growth and maturity in their life before they can reproduce sexually. This stage is known as Juvenile phase or Vegetative phase.

(b) Reproductive phase :
The end of juvenile phase is the beginning of reproductive phase. It can be seen easily in the higher plants when they come to flower.

Question 9.
Distinguish between asexual and sexual reproduction. Why is vegetative reproduction also considered as a type of asexual reproduction? [Mar. 15 – T.S.]
Answer:

1. When an offspring is produced by a single parent with or without the involvement of gamete formation it is called asexual reproduction.
2. Sexual reproduction involves the formation of the male and female gametes, either by the same individual or by different individuals of the opposite sex.
3. Vegetative reproduction does not involve two parents, hence it is also considered as a type of asexual reproduction.

Question 10.
Identify each part in a flowering plant and write whether it is haploid (n) or diploid (2n). [Mar. – 2018]
(a) Ovary _____ (b) Anther _____ (c) Egg _____ (d) Pollen _____ (e) Male gamete _____ (f) Zygote _____
Answer:
a) Ovary – Diploid (2n)
b) Anther – Diploid (2n)
c) Egg – Haploid (n)
d) Pollen – Haploid (n)
e) Male gamete – Haploid (n)
f) Zygote – Diploid (2n)

Question 11.
Give a brief account on the phases of the life cycle of an angidsperm plant.
Answer:

1. The life cycle of an angiospermic plant has two alternating phases namely the sporophytic and gametophytic phases.
2. In angiosperms the plant body belongs to diploid (2n) sporophytic phase. This dominant phase of life cycle bears reproductive organs (flowers).
3. The haploid (n) gametophytic phase of angiospermic plant is dervied from microspores (n) and megaspores (n).
4. Microspores (pollen grains) are the meiotic products of microspore mother cells that develop in an anther.
5. Megaspores are the meiotic products of megaspore mother cell that develop from the nucellus of the ovule.
6. Micro and megaspores produce male and female gametophytes respectively.
7. Male and female gametes formed respectively from male and female gametophytes are fused to form diploid (2n) zygote.
8. Zygote after undergoing repeated mitotic divisions produce embryo in the seed.
9. The embryo (2n) develops into a sporophytic plant during seed germination.

Long Answer Type Questions

Question 1.
Enumerate the differences between asexual and sexual reproduction. Describe the types of asexual reproduction exhibited by unicellular organisms.
Answer:
Differences between asexual and sexual reproduction :

Asexual reproduction by unicellular organisms :
It is by binary fission, budding and spore formation.

Binary fission :
Many unicellular organisms reproduce by binary fission. In this the parent cell divides into two equal halves and each one grows into new individuals. Eg : Euglena, bacteria etc. It is common in Protista and Monera.

Budding :
In yeast, asexual reproduction is done by budding. Small buds are produced that remain attached initially to the parent cell which eventually get separated and grows into new individual.

Spore :
In unicellular algae like Chlamydomonas asexual reproduction is done by spores. These spores are motile, hence called zoospores.

Question 2.
Although sexual reproduction is Song drawn, energy intensive complex forms of reproduction, many groups of organisms in kingdom plantae prefer this mode of reproduction. Give atleast three reasons for this.
Answer:

1. Sexual reproduction involves formation of the male and female gametes, either by the same individual or by different individuals of the opposite sex. These gametes fuse to form the zygote which develops to forms the new organism.
2. It is an elaborate, complex and slow process as compared to asexual reproduction.
3. Sexual reproduction results in offspring that are not identical to the parents or amongst themselves due to fusion of male and female gametes.
4. Sexual reproduction follow a regular sequence, and is characterized by the fusion (or fertilization) of the male and female gametes, the formation of zygote and embryogenesis. These sequential events may be grouped into 3 distinct stages namely, the pre-fertilization, fertilization and post-fertilization events.

A) Pre-fertilization events:
These include two events namely gametogenesis and gamete transfer that occur prior to the fusion of gametes. Gametogenesis refers to formation of two types (male and female) of gametes (haploid cells).

i) In some algae (eg. Cladophore) the two types of gametes may be so similar in appearance (isogametes) or may be two morphologidly distinct types (heterogametes) as in majority of sexually reproducing organisms. In plants that produce heterogametes (i.e., Runaria, Pteris and Cycas), the male gamete is called the antherozoid or sperm and the female gamete is called the egg.

ii) In some cases male and female gametes may be produced by same plant (bisexual), that has both male and female reproductive structures. In some other cases the male and female reproductive structures develop of two different plants of same species (unisexual). Bisexual condition can be denoted by terms such as homothallic (Fungi) and monoecious (plants). Similarly unisexual condition is described as heterothallic (Fungi) and dioecious (plants).

iii) In flowering plants, unisexual male flower being only stamen is called staminate and female flower bearing only pistils is called pistillate. In that case both male and female flowers may he present on same plant (monoecious cucurbits) or on two separate plants (dioecious – papaya and date palm).

iv) Organisms belonging to monera, fungi, algae and bryophytes have haploid plant body, they produce gametes by mitotic division. Whereas ptesido- phytes, gymnosperms and angiosperms having diploid plant body produce gametes through meiosis in meiocytes (gamete mother cells).

v) After the formation, male and female gametes must be physically brought together to facilitate fusion (fertilization). In majority of organisms (with exception of few fungi and algae), male gamete is motile and female gamete is stationary. In algae, bryophytes and pteridophytes water is the medium through which gamete transfer takes place.

vi) In seed plants pollen grains are the carriers of male gametes and ovule has the egg. in bisexual and self pollinating plants (Eg. Pea) pollen grains produced from anthers are transferred to stigma of same flower. But in cross pollinating plants (including dioecious) pollen from a flower reaches stigma of another flower).

vii) Pollen grains germinate on the stigma and pollen tubes carying the male gametes reach the ovule and discharge male gametes near the egg.

B) Fertilization :
It is the process of fusion of gametes and it is the most vital event of sexual reproduction. This process is also called as syngamy and result in the formation of a diploid zygote.
i) In majority of algae, syngamy occurs in the external medium (water) and is called external fertilization. But in many fungi and majority of plants (Bryophytes; Ptesidophytes, Gymnosperms and Angiosperms) syngamy (internal fertilization) occurs inside the body of the organism.

C) Post-fertilizaton events :
Events that occur after the formation of zygote are called as post-fertilization events. The diploid zygote is formed in all sexually reproducing organisms.

1. In fungi and algae with haplontic life cycle zygote develops a thick wall that is resistant to desication and damage, undergoes a period of rest before germination. In those organisms zygote divides by meiosis immediately after keryogamy to form haploid spores that grow into haploid individuals.
2. Zygote is the vital link that ensures continuity of species between organisms of one generation and the next.
3. Every sexually reproducing organisms begins life as a single called zygote.
4. Embryogenesis refers to the process of development of embryo from the zygote.
5. During embryogenesis, zygote undergoes cell divisions (mitosis) and cell differention (formation of tissues and organs) to form an organism.
6. In flowering plants, the zygote is formed inside the ovule, which transforms into seed. In angiosperms, seeds are present inside the fruit that formed from ovary.

Significance of sexual reproduction :

1. Sexual reproduction enables the organisms to survive during unfavourable con¬ditions by producing resistant structures (thick walled zygote, seeds), So, even Algae and Fungi that have predominance of asexual/vegetative reproduction in life cycle shift to sexual process just before the onset of adverse conditions.
2. Sexual reproduction involves fusion of gametes from two parents of opposite sex and hence responsible for genetic variation in offspring.
3. Seeds are useful to surpass unfavourable conditions. In viviporous Mangroves seeds germinate on mother plant itself. This is a strategy to lower the environmental stress and ensuring successful establishment of plant let.

Question 3.
Describe the post-fertilisation changes in a flower. [Mar. ’17 – A.P]
Answer:
Changes taking place in the angiospermic flower after fertilization are called post-fertilization changes.

1. Sepals, petals, stamens, styles and stigma fall off.
2. In some members of Solanaceae, calyx remains persistent even after fertilisation and grows along with the fruit. In Asteraceae, persistent calyx, pappus helps in the fruits dispersal.
3. After fertilization ovary develops into fruit. It stores food materials.
4. Fertilized ovules develop into seeds.
5. Part of ovule – Changes occurring after fertilization
   Funiculus – Stalk of the seed
   Outer integument – Testa (outer seed coat)
   Inner integument – Tegmen (inner seed coat)
   Micropyle – Seed pore
   Zygote – Embryo
   Synergids – Degenerate
   Antipodals – Degenerate
   Primary endosperm nucleus – Endosperm
   Scar of the ovule – Hilum (scar of the seed)

6) Endosperm is nutritive tissue useful for developing embryos. It is triploid in angiosperms and formed after fertilization.

Intext Question Answers

Question 1.
Why is reproduction essential for organisms?
Answer:
To ensure the continuity of species reproduction is essential. Reproduction will

1. replace those species that die and
2. allow an increase in total numbers of the species under suitable conditions.

Question 2.
Which is a better mode of reproduction sexual or asexual? Why?
Answer:
Sexual reproduction is the better mode of reproduction. It brings in diversity of characters in the new generation. It may give a better chance to adjust or adopt to changing environmental conditions, to tolerate diseases, to spread to new areas, to increase their population.

Question 3.
Why is the offspring formed by asexual reproduction referred to as clone?
Answer:
Offsprings formed by asexual method do not involve two parents. They are not only identical to one another but are also exact copies of their parent. Hence they are called clones.

Question 4.
How does the progeny formed from asexual reproduction differ from those formed by sexual reproduction?
Answer:
The progeny formed from asexual reproduction are genetically identical whereas those formed by sexual reproduction shows genetic variability.

Question 5.
What is vegetative propagation? Give two suitable examples.
Answer:
When the body breaks or gets separated into smaller portions, each fragment can develop into individual body. Eg: Algae, mould, mushrooms, ginger, turmeric, etc.

Question 6.
Higher organisms have resorted to sexual reproduction in spite of its complexity. Why?
Answer:

1. In sexual reproduction variants are found in the offspring and their survival rate was enhanced.
2. It gives better chance to adjust to changing environment.

Question 7.
Explain why meiosis and gametogenesis are always interlinked.
Answer:
Gametes are formed from meiocytes only after meiosis. This is called gametogenesis. Thus meiosis leads to the formation of gametes.

Question 8.
Define external fertilisation. Mention its disadvantages.
Answer:
In most aquatic organisms, such as algae, syngamy occurs in the external medium i. e., outside the body of the organism. This type of gametic fusion is called external fertilisation. Its disadvantage is they have to release a large number of gametes into the surrounding water in order to enhance the chances of syngamy.

Question 9.
Differentiate between a zoospore and a zygote.
Answer:
Zoospore is.a motile asexual spore that uses a flagellum for locomotion, also called a swarmspore, these spores are created by some algae, bacteria and fungi to propagate themselves.

Zygote is diploid, formed during sexual reproduction, by the fusion of male and female gametes.

Activity

Question 10.
Examine a few flowers of any cucurbit plant and try to identify the staminate and pistillate flowers. Do you know any other plant that ears unisexual flowers?
Answer:
Cucurbit plant show unisexual flowers. It bears only stamens in male flowers and only carpels in female flowers.

In coconut, male and female flowers are present on the same plant.

In Borasus, male flowers are present in male plant and female flowers are present in female plant.

Question 11.
What is a bisexual flower? Collect five bisexual flowers from your neighboured and with the help of your teacher find out their common and scientific names.
Answer:
The flower which has both androecium and gynoecium is called a bisexual flower. Collect different flowers as you collect for the herbarium.

Telangana TSBIE TS Inter 1st Year Botany Study Material 5th Lesson Morphology of Flowering Plants Textbook Questions and Answers.

TS Inter 1st Year Botany Study Material 5th Lesson Biological Classification

Very Short Answer Type Questions

Question 1.
Differentiate fibrous roots from adventitious roots. [Mar. – 2020]
Answer:
1) Adventitious roots :
The roots that arise from plant parts other than radicle.
Ex: Climbing roots, Velamen roots, Respiratory roots etc.

2) Fibrous roots :
Large number of roots which originate from the base of the stem after the loss of short lived primary root. Ex: Monocot plants.

Question 2.
Define modification. Mention how root is modified in banyan tree and mangrove plants ?
Answer:
1) Modification :
A permanent morphological change in a plant organ to perform a special function depending upon environment.

2) In banyan tree, roots are modified as prop roots (pillar roots) to give additional support for branches.

While in mangrove plants (Rhizophora and Avicennia) pneumatophores or respiratory roots come out of the ground and grow vertically upwards to get oxygen for respiration.

Question 3.
What type of specialized roots are found in epiphytic plants ? What is their function ?
Answer:
1. Velamen roots are found in epiphytic plants like Vanda.
2. They absorb moisture from the atmosphere.

Question 4.
How does the sucker of Chrysanthemum differ from the stolon of jasmine?
Answer:

1. Sucker of Chrysanthemum is the lateral branch arises from the basal and underground portion of stem. It grows obliquely upward giving rise to leafy shoot.
2. Stolon of jasmine is an obliquely downward growing slender lateral branch that arises from the base of the main axis and produces adventitious roots on touching the ground.

Question 5.
What is meant by pulvinus leaf base? In members of which Angiospermic family do you find them? [Mar. ’14 – A.P. ; Mar. ’14]
Answer:

1. The swollen leaf base is called pulvinus leaf base.
2. It is found in some members of leguminaceae family.

Question 6.
Define venation. How do dicots differ from monocots with respect to venation? [Mar. ’15 – A.P.]
Answer:

1. The arrangement of veins and the veinlets in the lamina of leaf is termed as venation.
2. Leaves of dicots have reticulate venation, whereas, leaves of monocots possess parallel venation.

Question 7.
How is a pinnately compound leaf is different from a palmately compound leaf? Explain with one example, each.
Answer:

1. Pinnately compound leaf: It consists of a number of leaflets on a common axis called rachis. Ex: Neem.
2. Palmately compound leaf: If consists of leaflets attached at a common point, i.e., at the tip of the petiole. Ex: Bombax ceiba (silk cotton).

Question 8.
Which organ is modified to trap insects in insectivorous plants? Give two examples. [Mar. 2019, ’13]
Answer:

1. Leaves are modified to trap insects in insectivorous plants.
2. Example : Nepenthes (Pitcher plant), Dionea (Venus fly-trap).

Question 9.
Differentiate between Racemose and Cymose inflorescences. [Mar. ’15 – T.S.]
Answer:

1. Racemose inflorescence: The main axis (Peduncle) continues to grow and produce flowers in an acropetal succession.
2. Cymose inflorescence: The main axis ends in a flower due to limited growth and flowers are borne in basipetal succession.

Question 10.
What is the morphology of cup like structure in Cyathium? In which family it is found? [Mar. – 2018, Mar. ’15 – A.P.]
Answer:

1. In Cyathium, involucre of bracts form cup like structure.
2. It is found in family Euphorbiaceae.

Question 11.
What type of inflorescence is found in fig trees ? Why does the insect B/astophaga visits the inflorescence of fig tree?
Answer:

1. Hypanthodium is found in fig trees.
2. The insect Blastophaga visits for pollination and lays its eggs in the gall flowers.

Question 12.
Differentiate actinomorphic from zygomorphic flower. [May ’14]
Answer:
1. Actinomorphic flower :
A flower that can be divided into two equal radial halves in any radial plane passing through the centre Ex: Hibiscus.’

2. Zygomorphic flower :
A flower that can be divided into two similar halves only in one particular vertical plane Ex: Bean.

Question 13.
How do the petals in pea plant are arranged? What is such type of arrangement called?
Answer:

1. In pea plant there are five petals. The largest (standard) petal overlaps the two lateral (wings) petals that inturn overlap the two smallest anterior petals (keel).
2. This arrangement is called vexillary or papilionaceous.

Question 14.
What is meant by Epipetalous condition ? Give an example. [May ’17, Mar. ’17 – A.P.]
Answer:

1. Epipetalous condition : A condition in which stamens attached to the petals.
2. Ex: Brinjal, Datura.

Question 15.
Differentiate between apocarpous and syncarpous ovary. [Mar. – 2018]
Answer:
1) Apocarpous ovary :
More than one carpel is present in gynoecium and they are free. Eg : Lotus and Rose

2) Syncarpous condition :
Carpels are fused. Eg: Mustard and Tomato.

Question 16.
Define placentation. What type of placentation is found in Dianthus? [Mar. – 2020, Mar. 15 – T.S.]
Answer:

1. The arrangement of ovules within the ovary is known as placentation.
2. In Dianthus, free central placentation is present.

Question 17.
What is meant by parthenocarpic fruit? How is it useful?
Answer:

1. A fruit formed without fertilization of the ovary is called parthenocarpic fruit.
2. They are without seeds. Ex: Banana.

Question 18.
What is the type of fruit found in mango? How does it differ from that of coconut?
Answer:

1. The type of fruit found in mango is drupe. In which the pericarp is well differentiated into an outer thin epicarp, a middle fleshy edible mesocarp and an inner stony hard endocarp.
2. In coconut, also fruit is a drupe in which the mesocarp is fibrous.

Question 19.
Why certain fruits are called false fruits ? Name two examples of plants having false fruits.
Answer:

1. Certain fruits that develop from floral parts other than the ovary called false fruits.
2. Ex: Apple (Thalamus) Cashew (Pedicel) Strawberry (Thalamus.)

Question 20.
Name any two plants having single seeded dry fruits.
Answer:

1. Dry indehiscent fruits are single seeded.
2. Coryza (caryopsis) and Tridax (Cypsela).

Question 21.
Define schizocarpic dry fruits. Give an example.
Answer:

1. The dry fruits which split into one Seeded bits called mericarps are known as Schizocarpic dry fruits.
2. Ex: Acacia, Castor.

Question 22.
Define mericarp. In which plant you find it?
Answer:

1. One seeded bits formed after splitting of Schizocarpic dry fruits are called mericarp.
2. Ex: Acacia, Castor.

Question 23.
What are aggregate fruits? Give two examples.
Answer:

1. Bunch of fruitlets developed from multicarpellary, apocarpous ovary are called aggregate fruits.
2. Ex: Custard apple (Annona squamosa), Strawberry.

Question 24.
Name a plant that has single fruit developing from the entire inflorescence. What is such a fruit called?
Answer:
Single fruit that develops from an entire inflorescence is called composite fruit. Ex: Pineapple, Jack fruit.

Short Answer Type Questions

Question 1.
Explain different regions of root with neat labeled diagram.
Answer:
Root has four regions. They are
a) Root cap
b) Region of rheristematic activity
c) Region of elongation
d) Region of maturation.

a) Root cap :
The tip of the root is covered by a thimble-like structure called the root cap. It gives protection to the root tip as it penetrates into the soil.

b) Region of meristematic activity :
Above the root cap, region of meristematic activity is present. It has meristematic cells. These cells are small, thin walled with dense protoplasm. They divide repeatedly.

c) Region of elongation :
Above the region of meristematic activity, region of elongation is present. The new cells formed grows and elongates. It is responsible for growth of length.

d) Region of maturation :
Behind the region of elongation region of maturation is present. Depending upon the function young cells differentiates into permanent cells. As it matures, it is called region of maturation.

From this region, some of the epidermal cells forms unicellular root hairs. The main function of root hairs is absorption of water from the soil. They are short lived.

Question 2.
Justify the statement: “Underground parts of plants are not always roots”.
Answer:
Normally roots are underground whereas stems are aerial. But in some plants stem grow below the soil. They are called underground stems. They are rhizome corm, stem tuber and bulb.

These underground parts of the plants can be recognised as stem due to presence of nodes, internodes, scale leaves, axillary buds and terminal buds. They can be even identified by their anatomical structures.

For example, stem tubers (Potato), these are underground branches which store food at the tip and becomes tuberous. The tuber is covered by brown coloured layer. It bears many ‘eye’ like structures. These eyes represent the nodes. Each eye has leaf scar and axillary bud. Scar represents the position of scale leaf. Eye help in vegetative propagation.

Question 3.
Explain with examples different types of phyllotaxy.
Answer:
The mode of arrangement of leaves on the stem and branches is called phyllotaxy. It is three types. They are
a) Alternate phyllotaxy :
In this type only one leaf arises at each node in alternate manner.
Eg : Hibiscus, rosa-sinensis (china rose), mustard, sunflower.

b) Opposite phyllotaxy :
In this type, a pair of leaves arise at each node and lie opposite to each other. Eg : Calotropis, Guava.

c) Whorl phyllotaxy :
In this type, more than two leaves arise at a node and form a whorl. Eg : Nerium, Alstonia.

Question 4.
How do leaf modifications help plants?
Answer:
The main function of leaf is photosynthesis and transpiration. In some plants leaves change in their structure to perform new function other than photosynthesis. This is called leaf modification.

1. Tendrils :
In weak stemmed plant, the entire leaf or any part of the leaf is modified into tendrils. They provide mechanical support and help in climbing. Eg: Pea.

2. Spine :
In some plants, leaves are modified into sharp pointed spines. They help in reducing the rate of transpiration in xerophytic plants and also for defence.
Eg: Cacti.

3. Storage leaves :
The fleshy leaves of onion and garlic store food materials.

4. Phyllode :
In some plants such as Australian acacia, the leaves are pinnately compound in which the leaflets are small and short lived. The petioles of these plants expand into green structure performing photosynthesis. These are called phyllode.

5. Insectivorous leaves :
In plants growing in nitrogen deficient soils, leaves are modified to trap insects for their nitrogen requirement.
Eg : Nepenthes (Pitcher plant)
Dionea (Venus fly trap)

6. Vegetative propagation :
In some plants leaves produce buds called epiphyllous buds. They help in vegetative propagation. Eg : Bryophyllum.

Question 5.
Describe any two special types of inflorescences.
Answer:
(Note : Write any two of the following 🙂
Verticellaster, Cyathium and Hypanthodium are special types of inflorescence.

Verticellaster:

1. It is a special type of inflorescence found in the family Lamiaceae (Labiatae).
2. In this type, flowers arise in the axil of leaves arranged opposite to each other at every node.
3. In the axil of leaf, the flowers are developed initially in dichasial cyme and later in monochasial scorpoid cyme.
4. Flowers are crowded round the node like a false whorl (verticel). Hence it is called ‘Verticellaster’.
   Eg: Leucas and Leonotis.

Cyathium :

1. This is a single flower like special inflorescence found in family Euphorbiaceae.
2. The inflorescence is covered by a deep cup like involucre of bracts.
3. At the centre of this cup there is a single female flower represented by tricarpellary syncarpous ovary.
4. Surrounding this female flower many male flowers are arranged in monochasial cyme.
5. Male flowers are represented by single stalked stamen. Male and female flowers are achlamydeous arranged in centrifugal manner. Eg: Euphorbia, Poinsettia.

Hypanthodium :

1. It is fruit like inflorescence.
2. In this peduncle is modified into a deep cup like fleshy structure with an apical opening.
3. The male flowers located near the opening and the female flowers are at the bottom while in between them the sterile female flowers called gall flowers are present.
4. Pollination in these plants takes place by an insect called Blastophaga which lay its eggs in the gall flowers. After fertilisation the whole inflorescence becomes into a fig fruit.

Question 6.
Describe the arrangement of floral members in relation to their insertion on thalamus.
Answer:
Depending upon the arrangement of floral members in relation to their insertion on thalamus, flowers are divided into three types. They are
1) Hypogynous :
Thalamus is conical. The gynoecium occupies the highest position. The remaining floral members like calyx, corolla and androecium are at the base of the gynoecium. In this the ovary is called “Superior”.
Ex : Hibiscus, Datura, Mustard, Brinjal etc.

2) Perigynous :
Thalamus is concave or saucer shaped. Gynoecium is situated at the centre. The remaining floral members like calyx, corolla and androecium are arranged along the margin, almost at the same level. In this, the ovary is said to be half inferior or half superior. Ex: Tephrosia, plum, rose, peach etc.

3) Epigynous flower :
In this, thalamus is deep cup like structure, inside it gynoecium is present. The walls of the thalamus and ovary are fused. The remaining floral members are arranged along the margins of the thalamus, i.e. above the level of ovary. So, the ovary is called inferior. Ex : Tridax, guava, cucumber, ray floret of sunflower.

Question 7.
“The flowers of many angiospermic plants which show sepals and petals, differ with respect to the arrangement of sepals and petals in respective whorls’. Explain.
Answer:
The arrangement of sepals and petals in floral bud is known as aestivation. It is of different types.

1) Valvate aestivation :
When sepals or petals in a whorl just touch one another at the margin without overlapping is called valvate aestivation. Eg : Calotropis.

2) Twisted aestivation :
When sepals or petals margin in a whorl overlap one another it is said to be twisted aestivation. Eg: Corolla of hibiscus, cotton, lady’s finger etc.

3) Imbricate aestivation :
If the margins of sepals or petals overlap one another but not in any particular direction is called imbricate aestivation. Eg : Cassia, gulmohur.

4) Vexillary or Papilionaceous aestivation :
In this, there are five petals. The largest petal towards posterior side is called Vexillum or Standard Petal. It overlaps the two lateral petals called Alae or wing petal. These overlap the two smallest petals called keel petals towards anterior side, which are boat shaped. Ex : Bean, Pea.

Question 8.
Describe any four types of placentations found in flowering plants.
Answer:
The arrangement of ovules within the ovary is known as placentation. They are Marginal placentation: Placenta forms a ridge along the ventral suture of the ovary. Ovules are borne on this ridge forming two rows. Eg: Pea

Axial placentation :
When the placenta is axial and ovules are attached to it in multilocular ovary, it is called axile placentation. Eg: China rose, rose, tomato and lemon.

Parietal placentation :
Ovules born on the inner wall of the ovary or on a parietal part, it is called parietal placentation. Ovary is one chambered but it becomes two chambered due to the formation of the false septum. Eg: Mustard and Argemone. Free central placentation : When the ovules are borne on the central axis without septa, it is known as free central placentation. Eg : Dianthus, primrose.

Basal placentation :
Single ovule is attached to placenta at the base of the ovary. It is called Basal placentation. Eg : Sunflower, marigold.

Question 9.
Describe in brief fleshy fruits by you studied.
Answer:
In fruits where pericarp becomes fleshy at the time of ripening are called fleshy fruits. Pericarp can be divided into three layers namely outer epicarp, middle mesocarp and inner endocarp. Basing upon the nature of pericarp, fleshy fruits are divided into five types. They are

1) Drupe :
It is one seeded fleshy fruit developed from monocarpellary, superior ovary. The fruit is characterised by stony endocarp. So it is known as Drupe.

In Mango, the outer epicarp is thin, middle mesocarp is fleshy and edible. The inner endocarp is hard stony.
In coconut, the outer epicarp is thin, middle mesocarp is fibrous and inner endocarp is hard stony. The edible part is the endosperm of seed (Copra).

2) Berry :
It is a fleshy fruit having one or more seeds. In this, epicarp is thin. Mesocarp and endocarp are fused to form pulp. Seeds are hard. These fruits develop from bi to multicarpellary syncarpous gynoecium: Eg : Guava, grapes, tomato.

3) Pome :
It is a fleshy fruit developed from inferior ovary of bi or multicarpellary syncarpous gynoecium. It is surrounded by fleshy thalamus. The endocarp is cartilagenous. Eg: Apple.

4) Pepo :
It is developed from tricarpellary syncarpous unilocular inferior ovary. The epicarp is like a rind., the mesocarp is fleshy and the endocarp is smooth. Eg : Cucumber.

5) Hesperidium :
It is developed from multicarpellary syncarpous, multilocular and superior ovary. In this epicarp is leathery with many volatile oil glands. Mesocarp is papery and endocarp has many chambers filled with juicy hairs. Eg : Citrus.

Question 10.
Describe with examples the various dry fruits studied by you.
Answer:
When the fruit wall or pericarp is dry or non-fleshy they are called dry fruits. They are of three types (i) Dry dehiscent (ii) Dry indehiscent (iii) Schizocarpic.
i) Dry dehiscent :
The dry fruit which break open and liberate the seeds are called dry dehiscent fruits. They are of different types.

a) Legume :
The fruits which break dorsiventrally into two halves liberating the seeds are called legumes. It is a characteristic fruit of family fabaceae. Eg : Pea, bean etc.

b) Capsule :
It is a dry fruit which liberates seeds in different ways at maturity. Eg : Cotton, Datura.

ii) Dry indehiscent fruits :
These dry fruits are normally one seeded and never dehisce even at maturity. The seeds are liberated only after the disintegration of the pericarp. They are of following types.

1) Caryopsis :
In this the pericarp and seed coat fuse together. It is a characteristic, . fruit of family poaceae. Ex: Grass, Rice.

2) Nut :
This single seeded dry fruit has a stony pericarp. The pericarp and seed coat remains free. Eg : Cashew.

3) Cypsela :
The single seeded fruit characterized by persistent pappus like calyx. Eg: Tridax.

iii) Schizocarpic fruits :
The fruit which split into one-seeded bits called mericarps are called schizocarpic fruits. Eg: Acacia, Castor.

Long Answer Type Questions

Question 1.
Define root. Mention the types of root systems. Explain how root is modified [Mar. 17 A.P & T.S ; Mar. 15 – A.P & T.S ; Mar. 13]
Answer:
The part of the plant body present below the soil is called root. It is developed from radicle. There are two types of root sytems.

1. Tap root system
2. Fibrous root system

In some plants root is modified to perform new function suitable for the environment. It is called root modification. They are
1) Storage roots :
The roots which store food materials are called storage roots or tuberous roots. In biennial plants, the tap root is modified into storage roots. Depending upon the shape, they are
a) Spindle shape (fusiform) Eg: Radish
b) Cone shape (Conical) Eg: Carrot
c) Top shape (Napiform) Eg: Beetroot
Adventitious roots of sweet potato and fibrous roots in Asparagus store food materials.

2) Prop roots or Pillar roots :
In plants like banyan trees, branches are large and heavy.
From the branches roots arise, they hang in air for sometime and later fixes into the soil.
They are called prop roots or pillars roots.
They act like pillars and gives support.

3) Stilt roots :
In plants like maize and sugarcane roofs arise from the lower nodes of the stem. They are called stilt roots. They give support to plant.

4) Pneumatophores or Respiratory roots :
The Mangrove plants which grow in swampy areas suffer from lack of oxygen as the soils are water lodged. In these plants root comes out of soil and grow vertically upwards. These roots are called respiratory roots or pneumatophores as they take oxygen from air for respiration.

5) Photosynthetic roots :
In Taeniophyllum (epiphyte) the stem and leaves are absent. The roots become green and perform photosynethsis. Such roots are called photosynthetic roots.

6) Velamen roots or Epiphytic roots :
The plants which grow on the branches of big trees for sunlight are
called epiphytes. They have roots which hang freely
in the air. They absorb moisture from the atmosphere. These roots are called velamen roots
or epiphytic roots. Eg : Vanda.

7) Nodular roots :
In members of Fabaceae, the roots show small nodule like structures. Hence it is called nodular roots. In the nodule, Rhizobium bacteria is present. It fixes atmospheric nitrogen into soil. Plant and Rhizobium show symbiotic association.

8) Parasitic roots or Kaustoria :
The plants which depend upon the other plants completely or incompletely for their food and water are called Parasites. They produce parastic roots. They are 1) Complete parasites 2) Partial parasites.
a) Complete parasitic piamts :
These are leafless. So the haustorial root enters into both xylem and phloem to obtain both water and food from the host plant. Ex : Cuscuta, Rafflesia.

b) Partial parasitic plants :
These plants bear leaves. So they can prepare food by photosynthesis. The haustorial roots penetrate only into the xylem tissue of the host to absorb water.

Question 2.
Explain how stem is modified variously to perform different functions. [Mar. 2020, 2019, 14, May 2017 ’14]
Answer:
When a permanent change occurs in the structure of stems to perform new functions suitable for the environment, it is called ‘stem modification’.

It is of three types. They are
I. Aerial stem modification
II. Sub aerial stem modification
III. Underground stem modification

I. Aerial stem modification :
Modification of aerial stems, vegetative buds and reproductive buds of a plant is called aerial stem modification.
a) Tendril :
Wiry delicate organ useful for climbing are called tendril. Axillary bud modified into tendril in gourds (cucumber, pumpkin, watermelon) or terminal bud in grapevines.

b) Thorn :
A woody pointed structure meant for protection are called thorns. Axillary bud modified into thorn. Eg : Bougainvillea. Terminal bud modified into thorn. Eg : Carissa.

c) Hook :
It is a woody, curved structure which helps in climbing. Ex : Artabotry.

d) Phylloclade :
Leaf like stem performing photosynthesis are called phylloclade. In order to reduce transpiration the leaves are modified into scales, spines etc.
Ex : In Opuntia, fleshy green flattened stem
In Euphorbia, fleshy green cylindrical stem In Casuarina green needle like stem.
Cladode or Cladophyll is a phylloclade of limited growth. Ex : Asparagus.

e) Bulbils :
Buds which show vegetative propagation are called bulbils. Vegetative buds in Dioscorea, Floral buds in Agave.

II. Sub aerial stem modification :
In some weak stemmed plants the stem remains partly aerial and partly underground. These are specialised for vegetative propagation. There are four types.

a) Runner:
Underground stems in some grasses and strawberry and sub-aerial stems in oxalis spread to new nitches and form new plants when older parts die.

b) Stolon :
In some plants slender branches arises grow obliquely downwards, produce roots at the point of contact with soil. These branches are called stolons. Ex : Nerium, Jasmine etc.

c) Suckers :
In plants like banana, pine apple, chrysanthemum part of the stem is in the soil. Underground branches grow obliquely upwards giving rise to leafy shoots. These branches are called suckers.

d) Offset :
In aquatic plants like Pistia and Eichhornia, a lateral branch of one internode length is called offset. At each node it bears a rosette of leaves and balancing roots at the base.

III. Underground stem modification :
Functions of the underground stems are storage of food materials, perennation through unfavourable seasons and vegetative reproduction. So these are called multipurpose stem modification.

a) Rhizome :
It is an underground stem which grows horizontally. It is branched. Ex: Zingiber (ginger).

b) Corm :
It is an underground stem which grows vertically. It is unbranched contractile roots present. Ex : Amorphaphallus (Zaminkand) and colocasia.

c) Stem tuber :
The swollen tip of an underground branch is called stem tuber. It bears many eyes. These eyes represent the nodes. Ex ; Potato.

d) Bulb :
It is a small reduced underground stem. Food is stored in the leaf bases. Ex: Onion.

Question 3.
Explain different types of racemose inflorescences.
Answer:
Types of racemose inflorescence.
1) Simple Raceme :
Peduncle is unbranched, grows indefinitely on its numerous pedicillate, bracteate flowers are arranged in accropetal manner.
Ex: Crotalaria.

2) Compound Raceme :
Peduncle is branched. Each branch resembles a simple raceme. Ex: Mangifera. It is also called Panicle.

3) Simple Corymb :
Peduncle is unbranched and grows indefinitely. On it numerous pedicillate, bracteate flowers are arranged in accropetal manner. The lower flowers have long pedicels and upper flowers have shorter pedicels. Thus all the flowers are brought more or less to the same height. Eg: Cassia.

4) Compound Corymb :
Peduncle is branched and each branch is produced into a simple corymb. Eg: Cauliflower.

5) Simple Umbel :
The peduncle is condensed and unbranched. Many bracteate and pedicellate flowers arise at the tip. At the base of flowers, all the bracts form a whorl called ‘involucre’. Ex: Onion.

6) Compound Umbel :
Peduncle is branched. Each branch produces a simple umbel at its tip. Ex : Carrot.

7) Simple Spike :
Peduncle is unbranched. On it bracteate, sessile flowers are arranged, accropetally. Ex : Achyranthes.

8) Compound Spike :
Peduncle is branched. Each branch is similar to simple spike. Ex: Grass (Poaceae family).

9) Simple Spadix :
Peduncle is unbranched. On it sessile, unisexual and neuter flowers are arranged in acropetal succession. It is protected by modified bract called ‘Spathe’. Ex: Colocasia.

10) Compound Spadix :
Peduncle is branched. Each branch is similar to simple spadix. Ex: Musa, Cocos.

11) Head inflorescence :
Unisexual and bisexual sessile flowers are arranged centripetally on a condensed peduncle. Such an arrangement of flowers is called Head inflorescence. Ex: Tridax, Sunflower (Asteraceae family).

Intext Question Answers

Question 1.
In which plant, the underground stem grows horizontally in soil and helps in perennation?
Answer:
Zingiber (ginger)
Curcuma (turmeric)

Question 2.
Needle like phylloclades are found in which plant?
Answer:
Casuarina

Question 3.
Why do plants like Nepenthes trap insects?
Answer:
For their nitrogen requirement

Question 4.
What is the characteristic inflorescence found in members of Asteraceae?
Answer:
Head inflorescence

Question 5.
Can you name a plant that has least number of flowers in its inflorescence?
Answer:
Single flower in Hibiscus and Datura

Question 6.
Which family shows naked flowers?
Answer:
Euphorbiaceae family

Question 7.
In which flowers of the fig trees does the insect Blastophaga lay its eggs?
Answer:
Gall flowers (Sterile female flowers)

Question 8.
What type of symmetry is shown by the flowers of Canna?
Answer:
Asymmetry (irregular)

Question 9.
On which side of the flower do the flowers of pea have the keel petals?
Answer:
Anterior side

Question 10.
What is the ratio of overlapping margins of petals to overlapped ones in imbricate aestivation?
Answer:
1 : 1

Question 11.
How many ovules are found attached in basal placentation?
Answer:
One ovule

Question 12.
Which part of the flower in cashew plant forms the false fruit?
Answer:
Pedicel

Question 13.
Which plant has hard, stony endocarp and fleshy edible mesocarp?
Answer:
Mango

Question 14.
What is the morphology of ’spathe’ in Spadix inflorescence?
Answer:
Bract

Question 15.
What is the type of fruit known as if it develops from apocarpous ovary of a single flower?
Answer:
Aggregate fruit

Telangana TSBIE TS Inter 1st Year Botany Study Material 4th Lesson Plant Kingdom Textbook Questions and Answers.

TS Inter 1st Year Botany Study Material 4th Lesson Plant Kingdom

Very Short Answer Type Questions

Question 1.
What is the basis of classification of Algae?
Answer:

1. Pigmentation and the type of stored food are the basis for classification of algae.
2. Based on above criteria algae are divided into 3 main classes-chlorophyceae Phaeophyceae and Rhodophyceae.

Question 2.
When and where does reduction division take place in the life cycle of a liverwort, a moss, a fern, a gymnosperm and an angiosperm?
Answer:

1. Liverwort – Sporophyte (capsule) – spore mother cell.
2. Moss – Sporophyte (capsule) – spore mother cells.
3. Gymnosperm – Sporophyte (Micro and mega sporangia) – Micro and megaspore
4. Angiosperm – Sporophyte (Anthers and ovule) – Spore mother cells

Question 3.
Differentiate between syngamy and triple fusion.
Answer:
1) Syngamy :
One of the two male gametes released from pollen tube fuses with the egg cell to form a diploid zygote. This is also called true or real fertilisation.

2) Triple fusion :
One of the two male gametes released from pollen tube fuses with the diploid secondary nucleus to produce the triploid Primary Endosperm Nucleus (PEN).

Question 4.
Differentiate between antheridium and archegonium.
Answer:

1. The antheridium is male sex organ whereas archegonium is female sex organ.
2. Antheridium produces many antherozoids (sperms), while archegonium produces an egg cell.

Question 5.
What are the two stages found in the gametophyte of mosses? Mention the structures from which these two stages develop?
Answer:

1. Protonema and Gametophore.
2. Protonema develops directly from the spore and adult gametophore develops from protenema.

Question 6.
Name the stored food materials found in Phaeophyceae and Rhodophyceae. [May ’14]
Answer:

1. The stored food materials found in Phaeophyceae are laminarin or mannitol.
2. The stored food material found in Rhodophyceae is floridian starch.

Question 7.
Name the pigments responsible for brown colour of Phaeophyceae and red colour of Rhodophyceae.
Answer:

1. The brown colour of Phaeophyceae depends upon the amount of xanthophyll pigment, fucoxanthin present in it.
2. The red colour of Rhodophyceae is due to red pigment r – phycoerythrin.

Question 8.
Name different methods of vegetative reproduction in Bryophytes. [Mar. 15 – A.P.]
Answer:
Fragmentation, gemmae and budding.

Question 9.
Name the integumented megasporangium found in Gymnosperms. How many female gametophytes are generally formed inside the megasporangium?
Answer:

1. Ovule
2. One female gametophyte with 2 or more archegonia is formed inside the megasporangium.

Question 10.
Name the Gymnosperms which contain mycorrhiza and corolloid roots respectively.
Answer:

1. Pinus contains mycorrhizal roots.
2. Cycas, contains corolloid robts.

Question 11.
Mention the ploidy of any four of the following.
a) Protonemal cell of a moss
b) Primary endosperm nucleus in a dicot
c) Leaf cell of a moss
d) Prothallus of a fern
e) Gemma cell in Marchantia
f) Meristem cell of monocot
g) Ovum of a liverwort
h) Zygote of a fern.
Answer:
a) Haploid
b) Triploid
c) Haploid
d) Haploid
e) Haploid
f) Diploid
g) Haploid
h) Diploid

Question 12.
Name the four classes of Pteridophyta with one example each.
Answer:
Cl : Psilopsida Ex : Psilotum
Cl: Lycopsida Ex : Selaginello, Lycopodium
Cl : Sphenopsida Ex : Equisetum
Cl : Pteropsida Ex : Dryopteris, Pteris, Adiantum

Question 13.
What are the first organisms to colonise rocks? Give the generic name of the moss which provides peat.
Answer:

1. Mosses and lichens are the first organisms to colonise rocks
2. Sphagnum, (a moss) provides peat.

Question 14.
Mention the fern characters found in Cycas.
Answer:
Fern characters found in Cycas are

1. Young leaves exhibit circinate vernation.
2. Presence of ramenta.
3. Male gametes are multiciliated.
4. Archegonia are present in the female gametophyte.

Question 15.
Why are Bryophytes called the amphibians of the plant kingdom?
Answer:
Bryophytes are called the amphibians of the plant kingdom because these plants live in moist soil and are dependent on water for sexual reproduction.

Question 16.
Name an algae which show
a) Haplo-diplontic and
b) Diplontic types of life cycles.
Answer:
a) Ectocarpus and Kelps (Laminaria) – haplo-diplontic life cycle.
b) Fucus – diplontic life cycle.

Question 17.
Give examples for unicellular, colonial and filamentous algae.
Answer:
Unicellular algae Ex : Chlamydomonas.
Colonial algae Ex : Volvox
Filamentous algae Ex : Spirogyra, Ulothrix.

Short Answer Type Questions

Question 1.
Differentiate between red algae and brown algae. [Mar. ’14]
Answer:

Question 2.
Differentiate between liverworts and mosses.
Answer:

Question 3.
What is meant by homosporous and heterosporous pteridophytes? Give two examples.
Answer:
The plants which produce only one kind of spores are called homosporous Ex: Psilotum, Lycopodium. The plants which produce two kinds of spores, macro or megaspores and microspores are called heterosporous Ex: Selaginella, Salvinia.

Question 4.
What is heterospory? Briefly comment on its significance. Give two examples.
Answer:
Producing two types of spores is called heterospory 1) Microspores 2) Megaspores.

Significance :
In heterosporous plants, the megaspores and microspores germinate and give rise to female and male gametophyte respectively. Male gametes are transferred to the egg of female archegonium. The female gametophytes retain on the parent sporophyte for variable period. The development of zygotes into young embryos takes place within the female gametophytes. This event is a precursor to the seed habit. It is considered as an important step in evolution.
Example : Selaginella and salvinia.

Question 5.
Write a note on economic importance of Algae and Bryophytes. [March 2019]
Answer:
Economic importance of Algae :

1. About 50% of carbon fixation is done by algae by photosynthesis. Thus by photosynthesis 02 is released into environment.
2. Algae are primary producers for all aquatic animals in food cycle.
3. Many species of Porphyra, Laminaria and Sargassum are among the 70 species of marine algae used as food.
4. Brown algae and Red algae produce large amounts of hydrocolloids (water holding substances) & algin (brown algae) and carrageen (red algae) which are used commercially.
5. Agar obtained from Gelidium and Gracilaria is used to grow microbes and preparations of ice-creams and jellies.
6. Iodine is extracted from kelps like Laminaria.
7. Chlorella and Spirullina are unicellular algae used as food supplements even by space travellers.

Economic importance of bryophytes (mosses) :

1. Mosses provide food for herbaceous mammals, birds and other animals.
2. Sphagum provides peat used as fuel, because of its water holding capacity, they are used as packing material for trans-shipment of living material.
3. Mosses along with lichens are the first organisms to colonise rocks and hence they have great ecological importance.
4. They decompose rock making it suitable for the growth of higher plants, hence, they play important role in plant succession.
5. Mosses form dense mats on the soil, they reduce the impact of falling rain and prevent soil erosion.

Question 6.
How would you distinguish Monocots from Dicots?
Answer:

Question 7.
Give a brief account of prothallus. [Mar. – 2020]
Answer:

1. Haploid spores give rise to gametophytic prothallus in pteridophytes.
2. Prothallus is small, thin, green and autotrophic thallus like structure.
3. Prothallus grows in cool, damp, shady places as it requires water for fertilization.
4. Prothallus bears sex organs. The male sex organs are called antheridia and the female sex organs are called archegonia.
5. These sex organs are multicellular, jacketed and sessile.
6. Antheridia produce male gametes called antherozoids. Archegonia has egg cell which is a female gamete.
7. Antherozoids require water to reach egg.
8. Zygote develops into embryo within the female gamete. This event is a precursor to the seed habit. It in considered as an important step in evolution.

Question 8.
Draw labelled diagrams of
a) Female thallus and male thallus of a liverwort
b) Gametophyte and sporophyte of Funaria.
Answer:
a)

b)

Long Answer Type Questions

Question 1.
Name three groups of plants that bear archegonia. Briefly describe the life cycle of any one of them.
Answer:
Bryophytes, pteridophytes and gymnosperms bear archegonia.

Life cycle of a Moss plant:

1. The gametophyte is a dominant phase.
2. Moss plant is a haploid gametophore.
3. It produces gametangia on separate branches of the same plant and hence monoecious.
4. The club shaped antheridia or antheridial branches produce biflagellate male gametes called “antherozoids”.
5. The flask shaped archegonia on archegonial branches produce eggs (female gamete) in their venter.
6. Antherozoids liberated swim in water to reach egg in the venter.
7. Union of one male gamete (antherozoid) and egg unite results in diploid zygote. This is called fertilization.
8. Zyeote is the first cell for sporophytic generation. Zygote develops into embryo. Embryo is retained within the archegonium.
9. It develops into semi parasitic sporophyte consisting of foot, seta and capsule.
10. The spore mother cells in the spore sac of the capsule undergo meiosis and forms a number of haploid spores of one kind. Hence Funaria is homosporous.
11. Spore is the first cell for gametophytic generation under favourable conditions, the spore liberated germinates to give rise to filamentous protonema.
12. The buds arising from the aerial branches of protonema develop into independent gametophores.

Question 2.
Describe the important characteristics of Gymnosperms.
Answer:
The important characters of Gymnosperms are :

1. All gymnosperms are perennial, growing as woody trees or bushy shrubs.
2. Vascular tissues are arranged into vascular bundles.
3. Flowers are absent, however, microsporophylls and megasporophyll usually aggregate to form distinct cones or strobili called male cones and female cones respectively.
4. Gymnosperms are heterosporous: Gymnosperms produce two types of spores- Microspores and megaspores. Microspores are produced in Microsporangium. They are called pollen grain. Megaspores are produced in Megasporangia. The megasporangia are integumented and are called ovules.
5. Ovules are borne on megasporophyll and have three layered integument with an opening called micropyle.
6. Pollination is indirect.
7. Fertilization is affected by pollen tube produced by the male gametophyte. It is called siphonogamy.
8. Endosperm is formed before fertilization. That means female gametophyte is considered as endosperm. It is haploid.
9. Seeds are naked i.e., without any seed coat.

Question 3.
Give the salient features of pteridophytes.
Answer:

1. The main plant body of pteridophyte is sporophyte. It is differentiated into true roots, stem and leaves.
2. Vascular tissues are present. So pteridophytes are commonly called vascular cryptogams.
3. Roots are adventitious.
4. Stem is underground rhizome.
5. The leaves of pteridophytes are small (microphyllous) as in selaginella or large fronds (macrophyllous) as in ferns.
6. Ferns show circinate vernation and the petioles are covered with brown multicellular hairs called ramenta.
7. The stele may be protostele or siphonostele or solenostel6.
8. One of the important characters of pteridophyte is that the sprophyte has become the dominant part of the life cycle while the gametophyte is reduced.
9. Gametophyte is small and inconspicuous and it is produced from haploid spores known as prothallus.
10. The asexual generation or the sporophyte may be homosporous (all spores are similar) or heterosporous (two different types of spores) i.e., microspores or megaspores.
11. Prothallus (gametophytes) are monoecicus or dioecious.
12. Sex organs are Antheridia and Archegonia.
13. Male gametes are Antherozoids formed from Antheridia. Antherozoids are uninucleate, spirally coiled, biflagellate or multiflagellate structures.
14. Union of male gamete and female gamete results in diploid zygote.
15. Zygote develops into Embryo stage.
16. True fruit and seeds are not formed at any stage.

Question 4.
Give an account of plant life cycles and alternation of generations.
Answer:
Plant life cycles :
1) Haplontic type of life cycle :

1. The dominant phase is gametophyte. It is photosynthetic free living.
2. Sporophytic generation is represented by zygote.
3. Zygote is a resting stage not a free living sporophyte.
4. Thus the life cycle having only free living gametophyte without free living sporophyte is called Haplontic type of life cycle. Ex :Algae like chlamydomonas, Volvox, Spirogyra etc.

2) Diplontic type of life cycle :

1. The dominant phase is sporophyte. It is photosynthetic independent plant.
2. Gametophytic generation is represented by gametes.
3. Thus the life cycle having only independent sporophyte without gametophyte is called Diplontic type of life cycle.
4. The life cycle having only independent sporophyte with few celled or many celled staged gametophyte is called diplo-haplontic type of life cycle.
   Ex: Pteridophytes and seed-bearing plants.

3) Haplo-diplontic type of life cycle :

1. The dominant phase is gametophytic generation. It is independent.
2. Sporophytic generation is photosynthetic dependent on gametophytic generation.
3. The life cycle having both dominant gametophytic generation and dependent sporophytic generation is called Haplo-diplontic type.

Interestingly most algae are haplontic. Some such as Ectocarpus and kelps are haplo-diplontic. Fucus is diplontic and Polysiphonia is diplo-biontic.

Alternation of generations:

1. In the life cycle of an organism two phases are present. They are Gametophytic phase and Sporophytic phase.
2. Haploid spore is the first cell for gametophytic generation.
3. Haploid spore divides mitotically and forms haploid gametophyte.
4. Gametophyte shows sexual reproduction. It forms male and female gametes.
5. The fusion of male and female gametes results in diploid zygote.
6. Diploid zygote is the first cell for sporophytic generation.
7. Diploid zygote divides mitotically and forms diploid sporophyte.
8. Diploid sporophyte shows asexual reproduction. It undergoes meiosis and forms haploid spores.

Thus during the life cycle of plants gamete producing haploid gametophyte alternates with spore producing diploid sporophyte. This is known as alternation of generation.

Question 5.
Both Gymnosperms and Angiosperms bear seeds, then why are they classified separately?
Answer:
Even though both Gymnosperms and Angiosperms bear seeds, they are classified separately because of nature of seeds.

In Gymnopserms:

1. The plant bears ovules which are not covered by any ovary wall. They remain exposed.
2. Pollination is direct.
3. Seeds formed are not covered by seed-coat. They are naked seeded plants.
4. Female gametophyte is considered as Endosperm as it is nutritive in function.
5. Endosperm is formed before fertilisation.
6. It is haploid.
7. Poly embryonic condition is present.

In Angiosperms:

1. The plant bears ovules which are present inside the ovary. They are not exposed.
2. Pollination is indirect.
3. Seeds formed are covered by seed – coat. They are closed seeded plants.
4. Endosperm is formed after double fertilisation and triple fusion.
5. Endosperm is triploid.
6. Single embryo is present.

Intext Question Answers

Question 1.
How far does SelagineJIa, one of the few living members of Lycopodiales (Pteridophytes) fall short of seed habit.
Answer:
Selaginella is heterosporous. It produces two kinds of spores. They are macrospores and microspores. Macrospores germinate and give rise to female gametophyte whereas Microspores give rise to male gametophyte. Fusion of male gamete with the egg present in the archegonium results in the formation of Zygote. The development of zygotes into young embryos takes place with the female gametophyte. This is the precusor to the seed habit.

Question 2.
Each plant or group of plants has some phylogenetic significance in the relation of evolution. Cycas, one of few living members of Gymnosperms is called as the “relic of past”. Can you establish a phylogenetic relationship of Cycas with any other group of plants that justifies the above statement?
Answer:
Cycas, one of Gymnosperms shows close resemblance with fern (pteridophyte) on one hand and angiosperms on the other hand. Thus occupying a position intermediate between the two.

Certain primitive characters in cycas are similar to ferns. They are

1. Stem when young is underground and subterranean.
2. Leaf bases are persistent on the stem.
3. Young leaves show circinate vernation.
4. The sporophylls are leaf-like.
5. Ramenta are present.
6. Xylem consists of tracheids only and there are no vessels.
7. Phloem lacks companion cells.
8. Microsporangia occur in sori on the abaxial side of microsporophyll.
9. Archegonia are still retained in the female gametophyte.
10. Sperms are multiciliate.

Question 3.
The male and female reproductive organs of several pteridophytes and Gymnosperms are comparable to floral structures of angiosperms. Make an attempt to compare the various reproductive parts of Pteridophytes and Gymnosperms with reproductive structures of Angiosperms.
Answer:

Question 4.
The plant body in higher plants is well differentiated and well developed. Roots are organs used for the purpose of absorption. What are the equivalent of roots in the less developed lower plants?
Answer:
Rhizoids. They are unicellular or multicellular hair-like structures that penetrate the moist soil and absorb the water for the plants.

Telangana TSBIE TS Inter 1st Year Botany Study Material 3rd Lesson Science of Plants – Botany Textbook Questions and Answers.

TS Inter 1st Year Botany Study Material 3rd Lesson Science of Plants – Botany

Very Short Answer Type Questions

Question 1.
Explain how the term Botany has emerged. [Mar. – 2009]
Answer:

1. The term Botany had its origin in the Greek language ‘Bous’ refers to cattle and ‘Bouskein’to cattle feed.’
2. In course of time, Bouskein was transformed into Botane and later into Botany.

Question 2.
Name the books written by Parasara and mention the important aspects discussed in those books. [Mar. ’20. ’17]
Answer:

1. Krishi Parasaram and Vrikshayurveda were the books written by Parasara. (1300 B.C.)
2. Krishi Parasaram the oldest book dealt with agriculture and weeds;, while Vrikshayurveda is about different types of forests, external and internal characters of plants including medicinal plants.

Question 3.
Who is popularly known as “Father of Botany”? What was the book written by him?
Answer:

1. Theophrastus is popularly known as Father of Botany.
2. Historia plantarum was the book written by him.

Question 4.
Who are Herbalists? What are the books written by them?
Answer:

1. Herbalists are botanists of Renaissance period of 16^th and 17^th centuries who identified and described medicinal plants living in natural surroundings.
2. The books written by them are called Herbais.

Question 5.
What was the contribution of Carolus Von Linnaeus’for the development of plant taxonomy?
Answer:

1. Carolus Von Linnaeus, the Sweedish Botanist popularised the Binomial Nomenclature System.
2. He also proposed the sexual system of classification.

Question 6.
Why is Mendel considered as the Father of Genetics?
Answer:

1. Mendel (1866) proposed the laws of inheritance based on his hybridization experiments on pea plant.
2. He marked the beginning of Genetics. Hence he is popular as the Father of Genetics.

Question 7.
Who discovered the cell and what was the book written by him? [Mar. ’14]
Answer:

1. Robert Hooke (1665) discovered the cell.
2. Micrographia was the book written by him.

Question 8.
What is Palaeobotany? What is its use? [May ’17, Mar. ’15 – T.S. : Mar. ’13]
Answer:

1. Palaeobotany is the study of fossil plants.
2. It helps in understanding the course of evolution in plants.

Question 9.
Name the branches of Botany which deal with the chlorophyllous autotrophic thallophytes and non-chlorophyllous heterotrophic thallophytes.
Answer:

1. The study of chlorophyllous autotrophic thallophytes (Algae) is Phycology.
2. The study of non-chlorophyllous heterotrophic thallophytes (Fungi) is Mycology.

Question 10.
What are the groups of plants that live as symbionts in lichens ? Name the study of lichens.
Answer:

1. Algal members (Phycobionts) and fungal members (Mycobionts) live as symbionts in lichens.
2. The study of lichens is called Lichenology.

Question 11.
Which group of plants is called vascular cryptogams? Name the branch of Botany which deals with them. [Mar. – 2018]
Answer:

1. Pteridophytes are called vascular cryptogams.
2. The branch which deals with pteridophytes is called Pteridology.

Question 12.
Which group of plants is called amphibians of plant kingdom? Name the branch of Botany which deals with them.
Answer:

1. Bryophytes are called amphibians of plant kingdom.
2. The branch which deals with bryophytes is called Bryology.

Short Answer Type Questions

Question 1.
Explain in brief the scope of Botany in relation to agriculture, horticulture and medicine.
Answer:

1. Agriculture, horticulture and medicine have recorded great progress through experiments in hybridization and genetic engineering.
2. New techniques of plant breeding are useful to develop hybrid varieties in crop plants like rice, wheat, maize, sugarcane etc.
3. The role of minerals in plant nutrition and the importance of hormones in plant growth helped in the development of agriculture.
4. Antibiotics like penicillin are obtained from fungi.
5. There are many plants like Arnica, Cinchona, Neem, Datura, Digitalis, Rauwolfia, Withania, Ocimum, Belladona, Aloe etc., which have medicinal values.
6. Using genetic engineering technique, cloned DNA s are produced which prepare hormoneslike insulin, interferon and vaccines.

Question 2.
Explain the scope of Botany taking plant physiology as example.
Answer:

1. The efforts made in plant physiology have helped the development of agriculture.
2. It provided the knowledge about role of minerals in plant nutrition and importance of hormones in plant growth.
3. Auxins at low concentration can form roots, so it is applied in agriculture and horticulture.
4. Gibberelins induce seed germination.
5. Cytokinins are used to enhance the shelf life period of leafy vegetables like spinach, lettuce etc.
6. Abscisic acid is used for delaying the sprouting of potato tubers under storage.
7. Ethylene accelerates the ripening of fruits like apple, banana, watermelons etc.

Question 3.
What are the different branches of Botany that deal with morphology of plants? Give their salient features.
Answer:
Morphology deals with the study and description of different organs of a plant. It is a fundamental requisite for classification of plants. It can be divided into two parts.
a) External Morphology :
It is the study and description of external characters of plant organs like root, stem, leaf, flower, fruit and seeds etc.

b) Internal Morphology :
It is the study of internal structure of different plant organs. It has two branches.

1) Histology :
It is the study of different tissues present in the plant body.

ii) Anatomy :
It deals with the study of gross internal details of plant organs like root, stem, leaf, flower etc.

Long Answer Type Questions

Question 1.
Give a comprehensive account on the scope of Botany in different fields giving an example for each.
Answer:

1. Man has been using plants for various purposes like food, clothes and shelter.
2. The global population is increasing rapidly. So to meet the demands of food and other challenges man depends on plants.
3. The problem of increasing population can be solved by increasing the crop production through “Green Revolution”.
4. Biotechnology is based upon the principles of molecular genetics, microbiology and biochemistry.
5. Biotechnology is applied for the production of medicine, chemicals, food, biofertilizers, biopesticides, disease resistant and pest resistant crops.
6. Agriculture, forestry, horticulture, floriculture have recorded great progress through experiments in hybridisation and genetic engineering.
7. New techniques of plant breeding are useful to develop hybrid varieties in crop plants like rice, wheat, maize, sugarcane etc.
8. Plant Taxonomy helps to study the diversity of plant kingdom by dividing plants into groups.
9. Plant pathology helped in prevention and eradication of several plant diseases.
10. Plant physiology helped the development of agriculture by providing knowledge about the role of minerals in plant nutrition and importance of hormones in plant growth.
11. Algae like spirulina and chlorella are good source of single celled proteins and vitamins.
12. Fungi like penicillin are good source for antibiotic.
13. Plants having medicinal value are Arnica, Cinchona, Neem, Datura, Rauwolfia, Withania, Ocimum, Belladona etc.
14. Plant fossils produce fuels like coal, coke, gasoline, petrol etc.
15. Recently bio-diesel is produced from jatropa and other petro plants belonging to the family Euphorbiaceae. Experiments in tissue and organ culture have made it possible to produce large number of plants within a short duration of time.
16. Industries like cloth mills, paper mills, sugar mills could be developed due to Botany.
17. Commercially important products like timber, fibres, beverages like coffee and tea, condiments, rubber, gums, resins, dyes, and essential and aromatic oils are obtained from plants.
18. Green plants reduce pollution, control greenhouse effect.
19. The hazardous effect of frequent use of chemical fertilizers have been reduced by using biofertilizers like Azolla, Nostoc, Anabaena, Rhizobium etc.
20. The Algae like Chlorella is used as food for astronauts in space research programmes.
21. Sand-binding plants help to check soil erosion and also control floods.
22. Several seaweeds are used in the extraction of iodine, agar-agar, etc.

Telangana TSBIE TS Inter 1st Year Botany Study Material 2nd Lesson Biological Classification Textbook Questions and Answers.

TS Inter 1st Year Botany Study Material 2nd Lesson Biological Classification

Very Short Answer Type Questions

Question 1.
What is the nature of cell walls in diatoms?
Answer:

1. In Diatoms, the cell walls form two thin overlapping shells, epitheca over hypotheca which fit together as in a soap box.
2. The walls are embedded with silica and are indestructible. The cell walls left behind by diatoms in their habitat and accumulate over billions of years as diatomaceous earth or kieselguhr.

Question 2.
How are Viroids different from Viruses?
Answer:

Question 3.
What do the terms phycobiont and mycobiont signify? [Mar. ’17, A.P. : Mar. ’13]
Answer:
1) Phycobiont :
The group of Algae that live as symbionts in lichens.

2) Mycobiont :
The group of fungi that live as symbionts in lichens.

Question 4.
What do the terms ‘algal bloom’ and ‘red tides’ signify?
Answer:
1. Algal bloom :
Excessive growth of algae mostly cyanophyceae members due to the enrichment of excessive nutrients in a water body. t

2. Red tides :
Sea appears red due to the rapid multiplication of a dinoflagellate, Gonyaulax Red tides in Meditarrenian sea.

Question 5.
State two economically important uses of heterotrophic bacteria.
Answer:

1. They help in making curd from milk.
2. They are helpful in nitrogen fixation in roots of leguminous plants.

Question 6.
What is the principle underlying the use of cyanobacteria in agricultural fields for crop improvement? [Mar. 2019, ’15 A.P]
Answer:

1. Cyanobacteria Eg : Nostoc, Anabaena, can fix atmospheric nitrogen in specialised cells called heterocysts.
2. They improve soil fertility by adding organic matter. ,

Question 7.
Plants are autotrophic. Name some plants which are partially heterotrophic.
Answer:

1. Insectivorous plants are partially heterotrophic.
   Eg : Bladderwort and Venus fly trap.
2. Parasitic plant, cuscuta is also partially heterotrophic.

Question 8.
Who proposed five kingdom classification ? How many kingdoms of this classification contain eukaryotes?
Answer:

1. R.H. Whittaker (1969) proposed Five Kingdom Classification.
2. Four kingdoms namely Protista, Fungi, Plantae and Animalia, consists of eukaryotes, while kingdom Monera consists of Prokaryotes.

Question 9.
Give the main criteria used for classification by Whittaker. [Mar. – 2020, 2018 • Mar. 15 – T.S.]
Answer:
The main criteria for five kingdom classification of Whittaker are cell structure, thallus organisation, mode of nutrition, reproduction and phylogenetic relationships.

Question 10.
Name two diseases caused by Mycoplasmas. [May ’14]
Answer:

1. Witches broom in plants.
2. Pleuropheumonia in cattle.
3. Mycoplasmal urethritis in humans.

Question 11.
What are slime moulds? Explain what is meant by plasmodium with reference to slime moulds.
Answer:
1. Slime moulds are saprophytic protists.

2. Plasmodium :
An aggregation formed by a slime mould under suitable conditions, which may grow and spread over several feet.

Short Answer Type Questions

Question 1.
What are the characteristic features of Euglenoids?
Answer:
Euglenoids:

1. These are unicellular, flagellate, fresh water organisms found in stagnant water.
2. Cell wall is absent.
3. The body is covered by thin flexible pellicle.
4. They bear two flagella, usually one long and one short. They swim actively by flagella.
5. The anterior part of the cell bears an invagination consisting of cytostome (cell mouth), cytopharynx (gullet) and reservoir.
6. A photosynthetic stigma or eye spot is present in the reservoir.
7. Chloroplast is present. The pigments in it are identical to those present in higher plants. Performs photosynthesis.
8. In the absence of sunlight they behave like heterotrophs depending on smaller organisms for food.,
9. Reproduction is by longitudinal binary fission Palmella stage is found in Euglena.

Question 2.
What are the advantages and disadvantages of two kingdom classification?
Answer:
a) Two kingdom classification with Plantae and Animalia was developed during cinnaeues tissue, that included all plants and animals respectively.

Question 3.
Give the salient features and importance of Chrysophytes. [Mar. – 2018, Mar. ’15 – A.P. : Mar. ’13]
Answer:

1. This group includes diatoms and desmids (golden algae).
2. They are green, microscopic, float in water currents.
3. In diatoms the cell walls form two thin overlapping shells, epitheca and . hypotheca which fit together as in a soap box.
4. The cell walls are embedded with silica which are indestructible. They pile at the bottom of water reservoir to form diatomaceous earth.
5. Diatoms are divided into two types based oh symmetry.
   i) CentraIe diatoms are radially symmetrical.
   ii) Pennales are bilaterally symmetrical.
6. Asexual reproduction is by binary fission and sexual reproduction is by the formation of gametes.

Question 4.
Give a brief account of Dinoflagellates. [Mar. 2019, ’17 – A.P, Mar. ’15 – T.S]
Answer:

1. Dinoflagellates are marine. They appear as yellow, green, brown, blue or red depending upon the pigments present in the cells.
2. Cell wall is made up of cellulose plates.
3. Two flagella are present. One lies longitudinally and the other lies transversely in the furrow between the wall plates.
4. Flagella produce spinning movements. So these are called whirling whips.
5. Nucleus is called Mesokaryon as chromosomes are condensed without histones.
6. Example : Nostoc shows bioluminescence.
   Gonyaulax make the sea appear red.

Question 5.
Write the role of fungi in our daily life. [Mar. ’14]
Answer:

1. Mushroom and toadstools are edible fungus.
2. Unicellular fungi like yeast are used to make beer and bread.
3. Fungi like Rhizopus commonly grow on stale bread, pickles, jams, cheese, on moist food stuff and spoils them. They are called moulds.
4. Fungi causes diseases in plants and animals.
   Eg : Wheat rust is caused by puccinia.
   Late blight of potato by phytopthora.
5. Orange rot, Red rot in sugarcane are caused by fungus.
6. White spots on mustard leaves are due to parasitic fungus. (Albugo)
7. Some fungi are the source of antibiotics and peninllium.

Long Answer type Questions

Question 1.
Give the salient features and comparative account of different classes of Fungi studied by you.
Answer:

Question 2.
Describe briefly different groups of Monerans you have studied.
Answer:
Kingdom Monera includes all prokarytes like Archebacteria, Eubacteria, Mycoplasma and Actinomycetes.

Archebacteria :

1. These are different type of bacteria as they have a different cell wall structure. They can survive in extreme conditions like salty areas (halophiles), hot springs (thermacidophiles) and marshy areas (methanogens).
2. The cell wall does not contain peptidoglycan as in bacteria but contain pseudomurein.
3. The cell membrane contains branched lipid which is responsible for their survival in extreme conditions.
4. Methanogens live in the guts of several ruminant animals like cowand buffaloes and help in their digestion.
5. They help in the production of,biogas such as methane from the dungs of the animals.

Eubacteria:

1. They occur everywhere even in extreme habitats.
2. They live as parasites, and symbionts also.
3. Basing on the shape bacteria are grouped under four categories. They are 1) Spherical coccus 2) Rod shaped Bacillus 3) Comma, shaped Vibrium 4) Spiral shape Spirillum
4. In Bacteria, cell wall consists of peptidoglycan also called murein or ‘ mucopeptide.
5. Infolding of cell membrane called mesosomes responsible for respiration.
6. Cell organelles are absent except ribosome.
7. As it is prokaryotic, the genetic material DNA is naked without nuclear membrane.
8. It shows autotrophic and heterotrophic nutrition.
9. Excessive growth of cyanobacteria due to nutrients present in sewage causes Algal blooms.
10. Rapid growth of red dinoflagellate like Gonyaulax make sea appear red or red tides in Mediterianian sea.
11. Chemo autotrophic bacteria oxidise various inorganic substances.
12. Chemo heterotrophs are saprophytes which grow on dead organic matter and parasite which causes diseases.
13. Asexual reproduction is mainly by binary fission or by spores during unfavourable condition. Sexual reproduction is done by transfer of genetic material from one bacteria to other.

Mycoplasma :

1. Mycoplasma are the smallest living cells and can survive without oxygen.
2. They do not have any cell wall.
3. Mostly they are pathogenic in plants and animals. They cause witches broom in plants, pleuropneumonia in cattle and mycoplasmal urethritis in humans.

Actinomycetes :

1. These are branched filamentous bacteria.
2. Cell wall contains mycolic acid.
3. Most of them are saprophytic and decomposers. Mycobacterium and Corynebacteriurn are parasites.
4. Antibiotics are produced from the genus Streptomyces.

Question 3.
Enumerate the salient features of different groups of protista.
Answer:
Kingdom Protista includes unicellular, aquatic, eukaryotes. It includes Chrysophytes, Dinoflagellates, Euglenoids, Slime moulds and Protozoans.
1. Chrysophytes:

1. It includes diatoms and desmids (golden algae).
2. They are green, microscopic, float in water currents.
3. In Diatoms the cell walls form two thin overlapping shells, epitheca and hypotheca which fit together as soap box.
4. The cell walls are embedded with silica which are indestructible. They pile at the bottom of water reservoir to form diatomaceous earth.
5. Diatoms are divided into two types based on symmetry.
   i) Centrale diatoms are radially symmetrical.
   ii) Pennales are bilaterally symmetrical.
6. Asexual reproduction is by binary fission and sexual reproduction is by the formation of gametes.

2. Dinoflagellates:

1. Dinoflagellates are marine. They appear as yellow, green, brown, blue or red depending upon the pigments present in the cells.
2. Cell wall is made up of cellulose plates.
3. Two flagella are present. One lies longitudinally and the other lies transversely in the furrow between the wall plates.
4. Flagella produce spinning movements. So these are called whirling whips.
5. Nucleus is called Mesokaryon as chromosomes are condensed without histones.
6. Example : Nostoc shows bioluminescence.
   Gonyaulax make the sea appear red.

3. Euglenoids :

1. These are unicellular, flagellate, fresh water organisms found in stagnant water.
2. Cell wall is absent.
3. The body is covered by thin flexible pellicle.
4. They bear two flagella, usually one long and one short. They swim actively by flagella.
5. The anterior part of the cell bears an invagination consisting of Cytostome (cell mouth), Cytopharynx (gullet) and reservoir.
6. A photosynthetic stigma on eye spot is present inthe reservoir.
7. Chloroplast is present. The pigments in it are identical to those present in higher plants. Performs photosynthesis.
8. In the absence of sunlight they behave like heterotrophs depending on smaller organisms for food.
9. Reproduction is by longitudinal binary fission Palmella stage is found in Euglena.

4. Slime moulds:

1. They show saprophytic nutrition.
2. Slime moulds are multinucleated protoplasm surrounded by plasma membrane.
3. They are aquatic; move along with decaying twigs.
4. Under favourable Conditions they aggregate to form plasmodium. They may spread upto several feet.
5. Under unfavourable conditions, plasmodium differentiates and forms fruiting bodies which bear spores at their tips. These spores are wind dispersed and can survive for many years.

5. Protozoans:
All protozoans are heterotrophs and live as parasites. The four major groups of protozoans are given below.
i) Amoeboid protozoans:

1. These organisms live in fresh water, sea water or moist soil.
2. They have locomotory organ called pseudopodia or false feet.
3. Marine forms have silica shells on their surface. Example: Amoeba.

ii) Flagellated protozoans:

1. These members are either free-living or parasitic.
2. They have flagella.
3. They cause diseases like sleeping sickness. Example : Trypanosoma.

iii) Ciliated protozoans:

1. These are aquatic and actively moving organisms because of cilia.
2. They have a cavity that opens to outside of the cell surface.
   Example : Paramecium.

iv) Sporozoans :
It includes diverse organisms that have an infectious sporelike stage in their life cycle. Example : Plasmodium.

InText Question Answers

Question 1.
State two economically important uses of
a) Heterotrophic bacteria.
b) Archaebacteria.
Answer:
a) Use of heterotrophic bacteria :

1. They help in making curd from milk.
2. They convert dead plants and animals into simpler substances and make them available to plants.

b) Use of archaebacteria :
1) They live in the guts of several ruminant animals such as cow and buffaloes and help in their digestion.

Question 2.
Give a comparative account of the classes of Kingdom Fungi on the basis of the following i) Mode of nutrition ii) Mode of reproduction.
Answer:

Question 3.
Give a brief account of viruses with respect to their structure and nature of genetic material. Also name four common viral diseases.
Answer:

1. Viruses are acellular, ultramicroscopic, nucleoprotein particles.
2. Viruses are obligate parasites. They are inert outside the host cell.
3. Viruses contain nucleic acid and protein.
4. The protein part forms a coat called capsid. It is made up of small sub units called capsomeres.
5. The nucleic acid which is genetic material may be DNA or RNA.
6. No virus contains both DNA and RNA.
7. Tobacco Mosaic Virus (TMV) and Human Immuno Virus (HIV) are examples for virus having RNA.
8. Bacteriophages contain DNA as genetic material.
9. Four common Viral Diseases : 1) AIDS, 2) Influenza 3) Small pox 4) Mumps.

Question 4.
Organise a discussion in your class on the topic. Are viruses living or non-living?
Answer:
The main points to be discussed in class :
a) Viruses can be regarded as living organisms because

1. They are formed by macromolecules which occur in living beings.
2. Presence of genetic material
3. Ability to multiply or reproduce
4. Occurrence of mutations
5. Infectivity and host specificity
6. Occurrence of antigenic property
7. Viruses are killed by autoclaving and ultraviolet rays.
8. Viruses are responsible for infectious diseases like common cold, influenza, chicken pox, mumps etc.

b) Viruses can be regarded as non-living organisms because

1. Protoplasm absents
2. Ability to get crystallized & TMV
3. Inability to live independently
4. High specific gravity which is found only in non-living objects
5. Absence of respiration
6. Absence of storing energy system
7. Absence of growth and division.

Question 5.
Suppose you accidentally find an old preserved permanent slide without a label and in your effort to identify it, you place the slide under microscope and observe the following features :
a) unicellular body
b) well defined nucleus
c) biflagellate condition – one flagellum lying longitudinally and the other transversely.
What would you identify it as ? Can you name the kingdom it belongs to?
Answer:
It is identified as Dinoflagellates.
It belongs to kingdom : Protista.

Question 6.
Polluted water bodies have usually high abundance of plants like IMostoc and Oscillatoria. Give reasons.
Answer:
Polluted water bodies have excessive growth of plants like Nostoc and Oscillatonia because of the excessive nutrients present in it. It results in algal booms.

Question 7.
Cyanobacteria and heterotrophic bacteria have been clubbed together in Eubacteria of kingdom Monera as per the five kingdom classification, even though the two are vastly different from each other. Is this grouping of the two types of taxa in the same kingdom justified? If so why?
Answer:
Yes. because both are unicellular prokaryotic organisms.

Question 8.
What observable features in Trypanosoma would make you classify under the kingdom Protista?
Answer:
They are aquatic, single-celled eukaryotes.

Question 9.
At a stage of their life cycle, ascomycetous fungi produce fruiting bodies like cleistothecium, perithecium or apothecium. How are these three types of fruiting bodies differ from each other?
Answer:

1. The fruiting bodies are produced in Fungi.
2. Ascomycetes are called Ascocarp.
3. The globose ascocarp without opening is called cleistothecium.
4. The flask-shaped ascocarp with an apical opening is called perithecium.
5. The cup or saucer-shaped ascocarp is called apothecium.

Telangana TSBIE TS Inter 1st Year Botany Study Material 1st Lesson The Living World Textbook Questions and Answers.

TS Inter 1st Year Botany Study Material 1st Lesson The Living World

Very Short Answer Type Questions

Question 1.
What does ICBINT stand for?
Answer:
ICBN stands for International Code for Botanical Nomenclature.

Question 2.
What is flora?

1. Flora is the actual account of habitat, distribution and systematic listing of plants of a given area.
2. It provides the index to the plant species found in a particular area.

Question 3.
Define Metabolism. What is the difference between anabolism and catabolism?
Aswer:

1. Metabolism refers to the sum total of all the chemical reactions occurring in the body of a living organism.
2. The constructive metabolic process in which complex molecules are formed from simpler molecules is called anabolism. The destructive metabolic process in which complex molecules are broken down into simpler molecules is called catabolism.

Question 4.
Which is the largest botanical garden in the world? Name a few well known botanical gardens in India.
Answer:

1. Royal Botanical Garden (RBG) at Kew, England is the largest botanical garden in the world.
2. Indian Botanical Garden, Howrah and National Botanical Research Institute, Lucknow are well known botanical gardens in India.

Question 5.
Define the terms couplet and lead in taxonomic key. [Mar. – 2018, Mar. 15, A.P.]
Answer:
1) Couplet :
A pair of contrasting characters that represents the choice made between two opposite options.

2) Lead :
Each statement in the taxonomic key.

Question 6.
What is meant by manuals and monographs? [May ’17, May ’14]
Answer:

1. Manuals are recorded descriptions useful in providing information for identification of names of species found in an area.
2. Monographs contain information on any one taxon.

Question 7.
What is systematics?
Answer:

1. Systematics is the study of different kinds of organisms, their diversities and also the relationship among them.
2. Systematics includes identification, nomenclature and classification. It takes into account evolutionary relationships between organisms.

Question 8.
Why are living organisms classified?
Answer:

1. Classification is the process by which anything is grouped into convenient categories based on some easily observable characters.
2. It is a device to study all the living organisms with ease.

Question 9.
What is the basic unit of classification? Define it. [Mar. ’20, ’17; Mar. 14, 13]
Answer:

1. Species is the basic unit of classification.
2. Species can be defined as a group of individual organisms with fundamental similarities. Eg : Solanum tuberosum (Potato)

Question 10.
Give the scientific name of Mango. Identify the generic name and specific epithet.
Answer:

1. The scientificname of Mango is Mangifera indica.
2. Mangifera is generic name and indica is specific epithet.

Question 11.
What is growth? What is the difference between the growth in living organisms and growth in non-living objects?
Answer:

1. Growth may be defined as permanent and irreversible increase in size overtime.
2. The growth in living organisms is from inside and by cell divisions. Whereas in non-living objects growth is due to accumulation of material on the surface.

Short Answer Type Questions

Question 1.
What is meant by identification and nomenclature? How is a key helpful in the identification and classification of an organism?
Answer:

1. Determining whether a collected plant is entirely new or already known is called identification. Providing a correct scientific name to an identified plant is called nomenclature.
2. Correct identification can be done by directly comparing the characters of the plant with an authentic herbarium specimen or indirectly with the help of key in floras.
3. Key or taxonomic key is an artificial analytic device having a list of statements with dichotomatic table of alternate characteristics which is used in identifying organisms.
4. Usually a couplet or two contrasting characters are used. The one present in the organism is chosen while the other is rejected.
5. Taxonomic key is helpful in the identification and classification of an organism based on.the similarities and dissimilarities.
6. Each statement in the key is called a lead.
7. Separate taxonomic keys are required for each taxonomic category such as family, genus and Species for identification purpose.

Question 2.
What are taxonomical aids? Give the importance of herbaria and museums.
Answer:
Herbarium, Botanical gardens, Zoological parks and Museums are taxonomical aids.

Herbarium:

1. Herbarium is a store house of collected plant specimen.
2. Plants identification can be done directly comparing the characters with an authentic herbarium specimen.
3. Plant specimens that are collected are dried, pressed and preserved on the sheets.
4. These sheets are arranged according to the system of classification.
5. These sheets provide the information about the date, place of collection, English name, local name and scientific name, family name even the collector’s name etc.
6. Herbaria serves as a quick referred system in taxonomic studies.
7. Royal Botanical garden at Kew, England has largest herbarium. It is an international centre for plant identification.
8. Nowadays herbarium is preserved as Digital herbarium. The digital images of the herbarium specimens and the related information is preserved and published on internet for wider use.

This digital herbarium is intended to take advantage of internet and digital photography technologies to provide online facility.

Museum :
Generally in schools and colleges biological museums are present. In these museums, they preserve the plants and animals specimens collected for study and reference. Specimens are preserved in the containers or jars in preservative solutions or they may be preserved as dry specimens.

Question 3.
Define a taxon. Give some examples of taxa at different hierarchial levels.
Answer:
Any system of classification is made up of different units such as species, genus, family, order, class, division, kingdom which are arranged in a hierarchial sequence. Irrespective of its rank in the sequence every unit is called Taxon.

Hierarchy is the arrangement of organism in a definite sequence. The following is the taxonomical categories showing hierarchial arrangement in ascending order.

Examples of Taxa at different hierarchial levels :

Question 4.
How are botanical gardens useful in conserving biodiversity? Define the terms Flora, Manuals, Monographs and Catalogues.
Answer:
Plants found in botanical gardens can be regarded as live specimens. Plants are grown in these gardens for identification purposes. Each plant is labelled indicating its botanical name and its family. Botanical gardens are useful in knowing our bioresources and their diversity.

Flora :
Flora is a book containing the details of the habitat and distribution of plants of a particular area. Every district in each state has its own flora.

Manuals :
These are small books useful in providing information for identification of names of species found in an area. It specially designed for ready reference.

Monograph :
They contain information on any one taxon.

Catalogues :
Books which help in correct identification of plants.

Question 5.
Explain binomial nomenclature.
Answer:

1. Every plant should have only one correct scientific name.
2. Every scientific plant name has two components. They are the generic name and the specific,epithet. This system of providing a name with two components is called Binomial nomenclature.
3. Scientific name should be in Latin or Latin derivative.
4. Both the words’ when handwritten they must be underlined or printed in italics to indicate their Latin origin.
5. The generic name will be in the noun form and always begins with capital letter. The specific name will be in the adjective form and starts with small letter. For example, Solanum tuberosum is the name of the potato plant in which “Solanum” is the genus and “tuberosum” is the species.
6. The author’s name may be given in abbreviated form at the end of the scientific name.

For example :
Mangifera indica Linn. It indicates that the species was first described by Linnaeus.

Long Answer Type Questions

Question 1.
What is meant by living? Give a detailed account of any four defining features of life forms.
Answer:
Organisms which are self replicating, evolving and self regulating, having interactive systems, capable of responding to external stimuli are said to be living.

The defining features of life forms are
1. Metabolism :
All living organisms are made of chemicals. These chemicals undergo various chemical reactions. The sum total of all the chemical reactions occurring in the body of a living organism is called metabolism. Cellular organisation of the body required for metabolism is the defining feature of life forms.

2. Consciousness :
Response to external stimuli is called irritability. Plants repond to external factors like light, water/temperature, other organisms, pollutants etc. All organisms are aware of their surroundings. This is called consciousness. Consciousness is the defining property of living organisms/Human being is the only one who is aware of himself that means has self consciousness.

3. Interactions :
Properties of tissues are not present in the constituent cells but arise as a result of interactions among the constituent cells. Similarly properties of cellular organelles are not present in the molecular constituents of the organelle but arise as a result of interactions among the molecular components comprising the organelle. Such underlying molecular interactions are also apparent in macromolecules such as starch. These interactions result in emergent properties at a higher level of organisation.

4. Genetic material :
All living organisms present, past and future are linked to one another by the sharing of common genetic material.

Question 2.
Define the following terms with examples, (i) Class (ii) Family (iii) Order (iv) Genus (v) Division.
Answer:
i) Class :
Class includes related orders. For example, in plant kingdom orders like Malvales, Rosales, Polemoniales etc., are included in the class : Dicotyledonae.

ii) Family :
Family is a group in which different genera of common characters are put together. Families are characterised on the basis of both vegetative and reproductive features of plant species. For example, three different genera Solanuim, Nicotiana, and Datura are placed in the family Solonaceae.

iii) Order :
Different families with similar characters are put into an order. The similar characters are less in number as compared to different genera included in a family. Plant families like Convolvulaceae, Solanaceae are included in the order Polemoniales mainly based on floral characters.

iv) Genus :
Genus is a group of different species with related characters. For example, potato and brinjal are two different species but belong to the genus-Solanum.

v) Division :
Different classes with similarities are grouped into division. Classes like Dicotyledonae and Monocotyledonae with a few similar characters are assigned to a higher category called division : Spermatophyta.

In the case of animals related classes are included in a phylum.

InText Question Answers

Question 1.
Some of the properties of tissues are not constituents of their cells. Give two examples to support the statement.
Answer:

1. Vascular tissues like xylem and phloem help in conduction of water, mineral salts and organic substances from one place to other.
2. Sclerenchyma tissue gives mechanical support to the plant body.

Question 2.
What do we learn from identification of individuals and populations?
Answer:

1. From the identification of individuals and population we learn their correct scientific names and the description of the organisms.
2. Identification is useful in agriculture, forestry to know our bioresources and their diversity.
3. Identification helps to determine whether a collected organism is entirely new or already known.

Question 3.
Given below is the scientific name of Mango. Identify the correctly written name, (i) Mangifera Indica (ii) Mangifera indica.
Answer:
Mangifera indica.

Question 4.
Can you identify the correct sequence of taxonomical categories ?
a) Species, Order, Division, Kingdom.
b) Genus, Species, Order, Kingdom.
c) Species, Genus, Order, Phylum.
Answer:
a) Species, Order, Division, Kingdom.

Question 5.
Define the following terms.
(i) Species (ii) Class (iii) Family (iv) Order (v) Genus.
Answer:
Species :
Species is the basic unit of classification. All those plants which are identical in all respects are regarded as species.

Class :
Class includes related orders. For example, in plant kingdom orders like Malvales, Rosales, Polemoniales etc., are included in the class : Dicotyledonae.

Family :
Family is a group in which different genera of comfhon characters are put together. Families are characterised on the basis of both vegetative and reproductive features of plant species. For example, three different genera Solanum, Nicotiana, and Datura are placed in the family Solonaceae.

Order :
Different families with similar characters are put into an order. The similar characters are less in number as compared to different genera included in a family. Plant families like Convolvulaceae, Solanaceae are included in the order Polemoniales mainly based on floral characters.

Genus :
Genus is a group of different species with related characters. For example: Potato and brinjal are two different species but belong to the Genus : Solanum.

Question 6.
Illustrate the taxonomical hierarchy with suitable examples of a plant.
Answer:
Flierarchy of categories is the arrangement of organisms in a definite sequence of categories. Descending order starts from kingdom to species. Ascending order starts from species to kingdom. This hierarchial system of classification was introduced by Linnaeus. The hierarchy includes seven categories – kingdom, division, or phylum, class, order, family, genus and species.

Question 7.
What are the distinctive characteristics exhibited by living organisms? Describe them in brief.
Answer:
The distinctive characters exhibited by living organisms are Growth, reproduction, irritability, metabolism, ability to self replicate, self organise, interaction and emergence.

Growth :
Living organisms grow by cell division. In animals growth is seen up to a certain age. However, cell division occurs in certain tissue to replace lost cells. In plants growth is present throughout the life.

Reproduction :
Production of progeny is referred on reproduction. Progeny are more or less similar to parents. Reproduction may be vegetative, asexual and sexual methods.

Irritability :
Response to stimuli is called irritability. Plants respond to external factors like light, water temperature etc. All organisms are aware of their surroundings and this is called consciousness.

Metabolism :
The sum total of all the chemical reactions occurring in the body of the living organism is called Metabolism.

Interaction and emergence :
Properties of cellular organelles are not present in the molecular constituents but as a result of interactions they emerge properties at next higher level of organisation.

Question 8.
Life forms exhibit ‘unity in diversity’ :
Discuss with your teacher.

Question 9.
List out the principles followed to provide scientific names for newly found organism.
Answer:

1. Every plant should have only one correct scientific name.
2. Every scientific plant name has two components. They are the generic name and the specific epithet. This system of providing a name with two components is called Binomial nomenclature.
3. Scientific name should be in Latin or Latin derivative.
4. Both the words, when hand written they must be underlined or printed in italics to indicate their Latin origin.
5. The generic name will be in the noun form and always begins with capital letter. The specific name will be in the adjective form and starts with small letter. For example, Solanum tuberosum is the name of the potato plant in which “Solanum” is the genus and “tuberosum” is the species.
6. The author’s name may be given in abbreviated form at the end of the scientific name.

For example :
Mangifera indica Linn. It indicates that the species was first described by Linnaeus.

Telangana TSBIE TS Inter 1st Year Ethics and Human Values Study Material 10th Lesson Ethics, Values and Thinking Textbook Questions and Answers.

TS Inter 1st Year Ethics and Human Values Study Material 10th Lesson Ethics, Values and Thinking

Question 1.
Discuss the importance of Ethics and how values can be inculcated.
Answer:

1. Importance : Ethics refers not merely to conformity with values of the society because of fear of retribution, but behaviour in accordance with the societal values because of having internalised them and having accepted them as one’s own.
2. Ethical behaviour also demands consistency of conduct and belief in a principle.
3. An individual is ethical if he behaves in accordance with a principle at all times and not just when it suits him.
4. If the above two conditions were absent, some of the very foundations on which the society is based, such as trust, acceptance and co-operation would crumble.
5. However, even when a society has a set of clearly defined moral principles, conflict is not necessarily avoided.
6. This is because ethics develops within specific social frame works and keep changing as societies change.
7. Thus, two societies are likely to uphold different, even opposing principles are priorities, which can because of conflict between them, even though certain primary ethical values may be almost universal in nature.
8. When people have good conduct and behave in conformity with the standards of the society, we call it ethical behaviour.
9. This can neither be taught nor learnt in the way other school subjects are taught.
10. It develops in individuals as a result of their family background, influence of their peer group and influence of the society in which they live.
11. The following factors influence the inculcation of values,
    a) Observation
    b) Participation
    c) Discussion
    d) Inspiration from others
    e) Fear of punishment
    f) Serious influence of some incidents or situations.
12. Thus inculcation of values for the progress and preservation of society is one of the key aims of Education.
13. Importance of inculcation of ethics or moral development has been echoed time and again by others thinkers, such as John Dewey, who posited that Education was a process of forming ‘Fundamental dispositions’.
14. Mahatma Gandhi is also quoted in this respect “The purpose of all knowledge is to build up character”.
15. For any value to be developed, it should be practised with regularity and without lapses.

Question 2.
Write an essay about the various aspects of Reflective Thinking.
Answer:
Reflection as a general skill can form part of the learning process. Reflection goes beyond just gaining knowledge, to

1. Exploring the foundations of that knowledge
2. Strengthening understanding
3. Increasing awareness of the values and attitudes that influence it.

Reflective process :
It was developed by Boud, Keogh and Walker. The process has three stages.

1. Returning to experience – a detailed recounting or recollection of the events.
2. Attending to the feelings, both positive and negative, that have been prompted by the experience.
3. Re-evaluating that experience in the light of these stages and the learner’s intent and self-knowledge, bringing in new knowledge that has been gained through the process.

The possible barriers of Reflections might be :

1. Assumptions about what is/is not possible.
2. Assumptions about how to learn.
3. Lack of confidence/self confidence.
4. Previous experiences.
5. Low expectations of others and of self.
6. Inadequate preparation.
7. Lack of amenable environment.
8. Lack of space/time.
9. Tiredness.
10. Unclear/ambivalent intent.

Reflection requires an approach which is

1. being tolerant of diversity of ideas – not every one will think the way you do, not everyone interprets or understands the world in the way you do.
2. being curious – there has to be a willingness to ask questions ,to want to find out.
3. being patient – just as there are no simple answers, there are no instant answers either and your ideas and understanding may well change over time.
4. being open – willingness to absorb what is happening.
5. being honest – you need to be honest with yourself and this includes being honest about doubts and uncertainity.

Question 3.
Differentiate between Critical Thinking and Creative Thinking.
Answer:
Critical thinking:

1. Critical thinking is exercising or involving careful judgement or evaluation.
2. Ex : Judging the feasibility of an idea or product.
3. Critical thinking is a very important skill to develop.

Critical thinkers are able to do the following things:

1. Be open minded about new ideas.
2. Be intellectually independent.
3. Know when there is a need for more information about something.
4. Ask questions.
5. Base their judgements on evidence.
6. Look for connections between subjects.
7. Analyze and understand concepts, information and behaviour.
8. Break things down and seperate fact from opinion.
9. Question everything that does not make sense.
10. Try to avoid common mistakes in reasoning.
11. Be honest with themselves.
12. Overcome confusion.
13. Try to separate emotional thinking from logical thinking. Creative thinking: A working definition of creative thinking is having unusual ideas and innovative thoughts and being able to put things together in new imaginative ways. It is like thinking outside of the box.

Tips to help you to develop your creative thinking skills:

1. Don’t get hooked on finding the right answer. There can be many right answers in a creative process. It depends on your point of view.
2. Don’t always be logical. Sometimes we need to look at some-thing in a very different or not so logical way to create a better way.
3. Break the rules sometimes. New break throughs have happened because of someone not always following the rules.
4. Be impractical. If we are always practical, we will always see things the same way. Sometime we have to step out what is usual or safe.
5. Allow yourself to fail. You get better with practice.
6. Always consider yourself to be creative. This goes to our never saying we cannot do something we need to always try.

Question 4.
What are some of the topics in your textbook on Ethics that you found interesting and useful? Discuss in brief.
Answer:
In this text book there are many Interesting topic and useful topics. Now I will discuss the topics unit wise.

Unit-I :
The topics like Good behaviour; character and conduct, Habit, Difference between good and bad are very good and useful to present day youth. The scope of Ethics is also good.

Unit – II :
In this unit constitution and the values embedded in Indian constitution is good.
In this topic Fundamental duties of Indian citizens are explained very clearly.

Unit – III :
This unit is exclusively for students. The importance or NCC and NSS are very clearly given. After reading this the kids will get interest in Bharath scouts and Guides.

Unit – IV :
In this unit Life Skill are really good. After readings this every student will follow how to Manage the time.
Peer pressure, Team work, Interpersonal relations are really Needed by each and every student.

Unit – V :
This chapter is very important for each and every citizen of India.

How to use Natural resource, what is the loss we are getting due to deforestation. How to control unethical practices will be know to each and every person who reads this.

Unit – VI :
This chapter defines what is religion. Differences between different religions. Importance of the religion. Greatiness of all religions is explained.

Unit – VII :
In this unit professional Ethics was discussed. IAS, IPS, officers, Doctors, Politicians etc play very important role in Building the society. If these people are corrupt there will be danger to Nation. Each professional person must go through this.

Unit – VIII :
In this unit Health and Nutrition was discussed. Especially nowadays all youth are doing dieting. After reading this book Every parent must give good and nutrition food to their kids.

Unit – IX :
The advantages, disadvantages of Internet, Mobile Phones, Computers are very clearly discussed in this unit.

Unit – X :
In this topic ethics was once again discussed. Reflective thinking, creative thinking is explained very nicely.