In maize,two plants that are both heterozygous for the recessive alleles a and b are crossed.What frequency of double-mutant progeny will appear if a and b are 7.2 map units apart,and both parents carry a and b in repulsion (trans)?
A)0.001296
B)0.005184
C)0.036
D)0.0625
E)0.072

Question

Quizplus · Accepted Answer

The correct answer is A because the frequency of double-mutant progeny is 0.001296. This is because the two genes are 7.2 map units apart, and the parents are in repulsion (trans). This means that the genes are on opposite chromosomes, and the probability of recombination between them is 0.072. The probability of getting a double mutant is the product of the probabilities of getting a mutant at each gene, which is 0.072 * 0.072 = 0.001296.

In Maize,two Plants That Are Both Heterozygous for the Recessive