Question

Pedigree analysis tells you that a particular parent may have the genotype AA BB or Aa BB, each with equal probability. Assuming independent assortment: (a) What is the probability of this parent producing an aB gamete? (b) What is the probability of this parent producing an AB gamete?

Im pretty sure (a) is 1/4 but I am confused on (b). If someone could thouroughly explain their reasoning for b that would be great.

Answer 1

Since (b) is asked in the question, I would explain that:

b)What is the probability of this parent producing an AB gamete

From AABB , we will get gametes : AB,AB,AB,AB :

The probability of producing an AB gamete is: 4/4 = 1

From AaBB, we will get gametes :AB,AB,aB,aB

The probability of producing an AB gamete is: 2/4 = 1/2

As per the question, both genotypes have equal probabilities, so the final probability of this parent producing an AB gamete would be:

1* (1/2) + 1* (1/2)

=1/2 + 1/2  

=1