in human beings, blue eyecolor is recessive to brown eyecolor. If a brown eyed man has a blue eyed mother, then find- a) what are the possible genotypes of his father? b) What is the genotype of the man and his mother.

Geneticists represent brown eyes with a B and blue eyes with a b. A brown-eyed person may be either BB or Bb. 

So the father’s genotypes may be either BB or Bb.

The mother is bb, since she has blue eyes, which is a recessive trait.

Hence the Son is Bb.