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he Law of Independent Assortment, , > The law of independent assortment states that the alleles of two or more genes behave, independently at the time of gamete formation and they mix up in all possible, combinations., , > Because of their independent assortment, besides the parental types, recombinant, varieties are also formed., , > The law of independent assortment can be explained by Dihybrid cross., , > The cross involving two pairs of contrasting traits of two characters is called dihybrid, cross., , >» Mendel crossed a true breeding pea plant with yellow and round seeds (YYRR) with a, true breeding pea plant with green and wrinkled seeds ( yyrr)., , > All Fl off springs are yellow, round phenotypically and double heterozygous, genotypically (YyRr)., , > Self fertilization between F1 plants resulted in the development of F2 generation., , > In F2 generation, 9/16 yellow round, 3/16 yellow wrinkled, 3/16 green round and 1/16, green wrinkled plants were formed., , > The phenotypic ratio of F2 generation is - 9, , > The genotypic ration of F2 generation is, 21, , , , , alsa), , , YR YR, eZ, P: YYRR «x yyrr, yellow, green,, round wrinkled, | { ye yr, YR, , Round/Yellow: 9, , as, , Round/green: 3, , self fertilisation wrinkled/Yellow: 3, , F,: YyRr, fond wrinkled/green: 1, 9:3:3:1 phenotypic, ratio, Back Cross & Test Cross L, , Test Cross, > Back cross between F1 hybrid (Tt), and homozygous recessive parent, , Cross between F1 hybrid and (tt) is called test cross., any one of the two parents is > This cross is called test cross because, called back cross. it helps to find out whether the given, Thus there will be two dominant F1 phenotype is, possibilities: homozygous or heterozygous., , > 1) Fl hybrid is crossed with A monohybrid test cross between F1, , Back Cross:, , homozygous dominant tall plant (Tt) and homozygous, ainda recessive parent (tt) will produce 50%, > 2) Fl hybrid is crossed with heterozygous tall and 50%, homozygous recessive homozygous recessive (tt). ie., ratio is, parent ( Tt x tt) 1:1, for both phenotype and, genotype.