Genetics - probability that the offspring

Question

A and B loci are 30 m.u. apart on a chromosome. If an A B / a b female mates with an a b / a b male, what is the probability that the offspring is A b / a b?

Answer 1

The A B / a b female can produce two types of gametes: AB and ab.

The a b / a b male can produce only one type of gamete: ab.

To calculate the probability of getting A b / a b offspring, we need to cross the gametes from the female with the gamete from the male:

AB x ab = AaBb

So, the offspring will be AaBb.

The probability of getting A b / a b is the probability of getting an A b gamete from the female (which is 1/2) times the probability of getting an a b gamete from the male (which is 1). Therefore, the probability is:

(1/2) x 1 = 1/2

So, the probability of the offspring being A b / a b is 1/2 or 50%.