A cell has alleles A and a at one locus. If a double strand break occurs within the A allele and gap repair synthesis is used to repair the break, what is the expected genotype after repair?

aa

Explanation:

The expected genotype after repair will be aa.

This can be explained by the fact that, the double strand (DNA structure) that have the information about A allele is lost because of the breakage, the DNA repair enzymes have the capability to synthesize the lost allele similar to allele of that gene present on their corresponding chromosomes.