Answer:
25%
Step-by-step explanation:
If the father is heterozygous for eye color, then he has one dominant brown allele and one recessive blue allele. The mother has blue eyes, so she must have two recessive blue alleles.
When these parents have a child, each parent randomly contributes one allele to the offspring. There are four possible combinations of alleles for the offspring: BB (brown eyes), Bb (brown eyes), bB (brown eyes), and bb (blue eyes).
To determine the probability of the offspring having blue eyes, we need to look at the possible combinations that result in blue eyes. The only way for the offspring to have blue eyes is if they inherit the recessive blue allele from both parents, which can only happen if the father contributes his recessive blue allele (b) and the mother contributes her recessive blue allele (b).
The father has a 50% chance of passing on the recessive blue allele, and the mother will always pass on a recessive blue allele. Therefore, the probability of the offspring having blue eyes is:
1/2 (chance of father passing on b allele) x 1/2 (chance of mother passing on b allele) = 1/4
So the probability of the offspring having blue eyes is 1/4 or 25%.