Question

With independent assortment, the ratio of genotypes in the F2 generation of a cross between true-breeding strains (AA bb x aa BB) can be described as 1:2:1:2:4:2:1:2:1. To what genotype does the "4" in the ratio refer?a. AA Bb
b. Aa BB
c. Aa Bb
d. None of the answer options is correct.

Answer 1

Answer:

c. Aa Bb

Explanation:

The parents were pure breeding with genotypes AAbb and aaBB. A cross between AAbb and aaBB would produce AaBb genotypes in F1 progeny. Two F1 strains would be crossed to produce F2 progeny. The F2 progeny would have the genotype ratio= 1:2:1:2:4:2:1:2:1.

Out of all the obtained genotypes in the F2 generation, the proportion of "AaBb" genotype was 4/16. Therefore, "4" in the given ratio represents the genotype "AaBb".