Here students can locate TS Inter 1st Year Botany Notes 4th Lesson Plant Kingdom to prepare for their exam.
TS Inter 1st Year Botany Notes 4th Lesson Plant Kingdom
→ Plant kingdom is divided into five groups : Algae, Bryopbytes, Reridophytes, Gymnosperms and Angiosperms.
→ Algae, Bryophytes, and Pteridophytes are non-flowering plants or Cryptogams. m Gymnosperms and Angiosperms are flowering plants or Phanerogams or Spermatophytes (seed-bearing plants).
→ Algae are simple, thalioid, autotrophic and aquatic plants.
→ Algae show vegetative, asexual and sexual methods of reproduction.
→ Algae are divided into three main Classes Chlorophyceae (Green algae)
→ Phaeophyceae (Brown algae) and Rhodophyceae (Red algae)
→ Bryophytes are primitive land plants.
→ Bryophytes are called amphibians of the plant kingdom because these plants live in moist soil and are dependent on water for sexual reproduction.
→ BryophytesInclude liverworts, hornworts and mosses.
→ In Bryophytes the plant body is thallus like and erect and attached to the substratum by unicellular or multicellular rhizoids.
→ The plant body in haploid and possesses root-like, leaf-like or stem-like structures. m The Bryophytes show haplontic type of life cycles.
→ The Pteridophytes are the first land plants having vascular bundles. m The Pteridophytes include club mosses, horsetails, ferns etc.
→ In Pteridophytes, the main plant body is a sporophyte which is differentiated into true roots, stem and leaves.
→ Gametophytes are small, inconspicuous, multicellular, photosynthetic thalioid called thallus.
→ Majority of plants are homosporous. Some plants like selaginella and salvinia are heterosporous.
→ The development of zygotes into young embryos takes place within the female gametophyte. This has led to the seed habit during the course of evolution.
→ The Gymnosperms are naked seeded plants.
→ Ginkgo is considered to be as living fossil.
→ The roots are generally tap roots – Mycorrhiza roots .(Pinus) and Coralloid roots (Cycas) are present.
→ Anatomically stem shows eustele.
→ The sporophylls (microsporophyll and megasporophyll) are arranged spirally on the axis to form male and female cones respectively.
→ Microspores are produced from microsporophyll.
→ Microspores develop into a male gametophytic generation which is highly reduced.
→ It is called pollen grain.
→ Megasporophyll with ovules are called megasporangiate (similar to female flower) Pollen grain germinates and the pollen tube releases male gamete in the ovule. Union of male gamete with female egg cell results in diploid zygote.
→ Zygote develops into embryo, and the ovules into seeds.
→ Angiosperms are embryophytic, non-archegoniate, vascular, fruit-bearing phanerogams or spermatophytes.
→ Angiosperms are large group of plants occurring in wide range of habitats. Angiosperms develop flowers. ‘
→ Male sex organs are called stamens and female sex organs are called pistil or the carpels.
→ Pollination is indirect in Angiosperms.
→ Pollen tube enters the embryo sac and discharges two male gametes. One male gamete unites with the egg resulting zygote. Other male gamete unites with the secondary nucleus to form primary endosperm nucleus. .
→ During the life cycle of any sexually reproducing plant, there is an alternation of generations between gametophyte and sporophyte.
→ Haplontic, diplontic or diplo-haplontic life cycles can be observed in different groups.