Class 12th Biology 2016 Set2 Outside Delhi Board Paper Solution
Give a genetic explanation for the following cross. When a t all pea plant with round seeds was crossed with a dwarf pea plant with wrinkled seeds then all the individual of F 1 -population were tall with round seeds. However selfing among F 1 -population led to a 9:3:3:1 phenotypic ratio.
Phenotypic ratio —
Tall Tall Dwarf Dwarf
Round Wrinkled Round Wrinkled
9 : 3 : 3 : 1
Law of dominance: In a dissimilar pair of factors one member of the pair is domin ant and the other is recessive. In the given cross tall and round are dominant where as dwarf a nd wrinkled are recessive (explain with or without a cross)
Law of Segregation: Allelic pairs seperate or segregate during gamete formation and the paired condition is restored during fertilisation (explain with or without a cross )
Law of Independent Assortment: The new combination seen in F 2 generation (Tall wrinkled) (Dwarf round) is only possible when the two gene pairs for height and seed shape (assort) independently of each other during gamete formation / The law states that when two pairs of traits are combined in a hybrid segregation of one pair of characters is independent of the other pair of characters
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