Question

In a cross between Aa males and Aa females, what is the expected F2 phenotypic ratio?

a) 1:2:1 (Apterosus:Apterous)
b) 3:1 (Apterous:Normal wing size)
c) 1:1 (Apterous:Normal wing size)
d) 4:0 (Apterous:Normal wing size)

Answer 1

The expected F2 phenotypic ratio in a cross between Aa males and Aa females is 3:1 (Apterous:Normal wing size).

Step-by-step explanation:

In a cross between Aa males and Aa females, the expected F2 phenotypic ratio is 3:1 (Apterous:Normal wing size). This is because the Apterous (A) allele is dominant over the normal wing size (a) allele.

When two heterozygous individuals (Aa) are crossed, they can produce offspring with two possible genotypes: AA (Apterous) or Aa (Apterous). The genotype ratio is 1:2, and since the phenotype is determined by the dominant allele, there will be a 3:1 ratio of Apterous to normal wing size individuals in the F2 generation.