NEETZoologyPrinciples of Inheritance and Variation
Match List-I with List-II regarding the expected phenotypic ratios in the progeny of different dihybrid crosses involving independently assorting genes. List-I List-II A. Selfing of F₁ dihybrid (both genes show complete dominance) I. 1:1:1:1 B. Selfing of F₁ dihybrid (one gene shows complete dominance, other shows incomplete dominance) II. 9:3:3:1 C. Selfing of F₁ dihybrid (both genes show incomplete dominance) III.
Options
- AA-II, B-IV, C-III, D-I
- BA-I, B-III, C-IV, D-II
- CA-II, B-I, C-IV, D-III
- DA-II, B-III, C-IV, D-I
Correct answer
D. A-II, B-III, C-IV, D-I
Step-by-step solution
The phenotypic ratio of a dihybrid cross involving independently assorting genes can be obtained by multiplying the monohybrid phenotypic ratios of the individual genes. A. Both genes show complete dominance: The monohybrid ratio is 3:1 . The dihybrid ratio is (3:1) (3:1) = 9:3:3:1 . B. One gene shows complete dominance ( 3:1 ) and the other shows incomplete dominance ( 1:2:1 ): The dihybrid ratio is (3:1) (1:2:1) = 3:6:3:1:2:1 . C. Both genes show incomplete dominance: The monohybrid ratio is 1:2:1 . The dihybrid