Question

Genes A and B are linked with recombination frequency of 0.2. Both genes segregate dominant (A and B) and recessive alleles (a and b). The parental cross AABB x aabb is performed and then the F1 progeny is testcrossed to aabb. If 10 individuals are counted in the F2, how many are expected to have recombinant phenotypes?

a) 2
b) 4
c) 6
d) 8

Answer 1

The expected number of individuals with recombinant phenotypes in the F2 generation is 2.

Step-by-step explanation:

The recombination frequency between genes A and B is 0.2, which means that 20% of the offspring will have recombinant phenotypes.

In the parental cross AABB x aabb, all of the offspring in the F1 generation will have the genotype AaBb. When the F1 individuals are testcrossed with aabb, the expected offspring in the F2 generation will have a 20% chance of having recombinant phenotypes.

Since there are 10 individuals in the F2 generation, we can calculate that 20% of 10 is 2. Therefore, the expected number of individuals with recombinant phenotypes in the F2 generation is 2.