Mushtaq has three grandparents with brown eyes and one with blue eyes.Raisa has two grand parents with brown eyes and two with blue eyes.Mushtaq and Raisa marry and have two children, both with brown eyes.What is the best estimate of the probability that their next child will have blue eyes?

Explanation

Mushtaq has three grandparents with brown eyes and one with blue eyes, and Raisa has two grandparents with brown eyes and two with blue eyes. Both likely have the genotype Bb, indicating that they each have one allele for brown eyes (B) and one for blue eyes (b). When both parents are Bb, their children's possible genotypes are BB (brown eyes), Bb (brown eyes), Bb (brown eyes), and bb (blue eyes). Thus, the probability of a child having blue eyes (bb) is 1/4.Option B is correct, as it correctly identifies the probability as 1/4 based on the potential genetic combinations. Option A is incorrect as it underestimates the likelihood of the child having blue eyes. Option C is incorrect as it provides a probability not consistent with the genetic possibilities. Option D is incorrect as it overestimates the probability, not accounting for the dominance of the brown eye allele.