Question

In a diploid plant, genes A and B are linked and are located very close to each other. Single crossovers between these two genes occurs only in 1 out of 16 meioses. If an individual has the genotype Ab/aB, explain what percentage of its gametes are expected to be recombinant (either AB or ab)?

Answer 1

3.125% of the gametes will be recombinant.

Step-by-step explanation:

One single crossover involves 2 out of 4 chromatids of the homologous chromosmome pair. Every time a single crossover event occurs, two parental gametes and two recombinant gametes are generated (so half the times a single crossover occurs the resulting gametes will be parental and the other half they will be recombinant).

If the frequency of crossing over events between genes A and B is 1/16 = 6.25%, half those times the resulting gametes will be recombinant (3.125%).