Question

A gene that has two alleles, A and a, is located on the same chromosome as a second gene that also has two alleles, B and b. Suppose a diploid individual has alleles AB on one copy of this chromosome and alleles ab on the other copy of this chromosome. For this individual, select the pair of recombinant genotypes that could result if crossing over occurs between these two chromosomes.
1. AB and aB2. Ab and ab3. Ab and aB4. AB and ab

Answer 1

Answer:

The correct answer to the question: For this individual, select the pair of recombinant genotypes that could result if crossing over occurs between these two chromosomes, would be, 3. Ab and aB.

Explanation:

During meiosis, the copy and distribution of genetic information present in genes, and which happens when chromosomes are divided and then crossed over, is a pretty unique one.

Essentially, genetic recombination happens when genes cross over and combine with genes present close to them. This process does not always happen and it is the reason why we say that some gametes are parental, instead of recombinant; because the genes in the chromosomes, especially depending on factors like distance between them, do not combine.

In this particular case, given the way that genes will cross over and knowing how recombination works, we could say that the possible genotypical recombinants for AB on chromosome 1 and ab on chromosome 2 would be the ones offered in option 3.