A triploid of genotype a b/a B/a b is crossed to a triploid of genotype A b/a b/a b.If genes A (a)and B (b)are 20 map units apart,what proportion of the progeny will be phenotypically A B?
A)1/3
B)1/4
C)1/6
D)1/9
E)1/36

Question

Quizplus · Accepted Answer

The probability of a crossover between the genes is 20%, and the probability of no crossover is 80%. The triploid can produce gametes with different combinations of alleles. The probability of getting an AB phenotype from the cross is calculated by considering the possible gamete combinations and the crossover probability, resulting in a 1/6 chance.

A Triploid of Genotype a B/a B/a B Is Crossed