Question

Refer to the figure showing a cell with two pairs of homologous chromosomes in prophase I of meiosis. Genes A (alleles A and a) and D (alleles D and d) are located on the longer pair of chromosomes, and gene B (alleles B and b) is located on the shorter pair.

Suppose 100 cells like the one shown go through the process of meiosis. However, only 20 of the cells have a crossover event that occurs between the A and D loci. Assuming that all 100 cells complete meiosis to produce a total of 400 haploid daughter cells, how many of the daughter cells would be expected to have the genotypes BAD or bad?

Answer 1

Answer:0.5(50%)

Step-by-step explanation:

Probability of B and b-0.5 each

probability of A,D-0.5 and a,d-0.5 as they are on same chromosome, therefore during meiosis cells takes one chromosome each with both AD or ad genes.

probability of BAD-0.5*0.5=0.25(25%)

probability of bad-0.5*0.5=0.25(25%)

combined probability of BAD and bad-0.25+0.25=0.5(50%)