{"id":35070,"date":"2022-11-22T10:39:25","date_gmt":"2022-11-22T05:09:25","guid":{"rendered":"https:\/\/tsboardsolutions.com\/?p=35070"},"modified":"2022-11-23T16:07:27","modified_gmt":"2022-11-23T10:37:27","slug":"ts-inter-2nd-year-botany-notes-unit-3","status":"publish","type":"post","link":"https:\/\/tsboardsolutions.com\/ts-inter-2nd-year-botany-notes-unit-3\/","title":{"rendered":"TS Inter 2nd Year Botany Notes Unit 3 Genetics"},"content":{"rendered":"

Here students can locate TS Inter 2nd Year Botany Notes<\/a> Unit 3 Genetics to prepare for their exam.<\/p>\n

TS Inter 2nd Year Botany Notes Unit 3 Genetics<\/h2>\n

\u2192 The biological science that deals with the study ofheriditary and variation is known as Genetics.<\/p>\n

\u2192 Gregor Johann Mendel proposed the ‘laws of inheritance\u2019 those led down foundation of the Genetics through his famous hybridization experiments on Phisum sativum.<\/p>\n

\u2192 Law of segregation states, that “the two alleles of a gene present together in het-erozygous state, do not fuse, remain distinct and segregate during meiosis.<\/p>\n

\u2192 Law of independent assortment states that “Genes for different characters are inherited independently of one other”.<\/p>\n

\u2192 The dominant characters are expressed when factors are either in homozygous or in heterozygous condition. (law of dominance)<\/p>\n

\u2192 The recessive characters are expressed only in homozygous condition. Different com- biriations of gametes are theoretically represented in a square tabular form known as “Punnett square.”<\/p>\n

\u2192 A cross involving a F1<\/sub> individual and any one of its parents is called Back cross.<\/p>\n

\u2192 A cross between a F1<\/sub> individual and its double recessive parents is called Test cross.<\/p>\n

\"TS<\/p>\n

\u2192 Monohybrid cross: Phenotypic ratio is 3 :1 and genotypic ratio is 1; 2:1.<\/p>\n

\u2192 Dihybrid cross: Phenotypic ratio is 9:3:3:1 and genotypic ratio is 1:2:2:4:1:2 : 1:2:1.<\/p>\n

\u2192 Mendel\u2019s laws were extended in the form of “Chromosomal theory of inheritance.”<\/p>\n

\u2192 Later it was found that Mendel’s law of independent assortment did not hold true for the genes that are located on the same chromosomes. These genes are called linked genes.<\/p>\n

\u2192 Closely located genes assorted together and distantly located genes, due to recombi-nation, assorted independently.<\/p>\n

\u2192 Mutations involves changes in chromosomes and\/or genes. They help to increase variability which might be useful in crop improvement<\/p>\n

\u2192 Gregor Johann Mendel:<\/p>\n