If a father and son are both defective in red-greenn colour vision, is it likely that the son inherited the trait from his father? Comment.

Explanation

Gene for colourblindness is X-chromosome linked, and sons receive their sole X-chromosome from their mother, not from their fathe. Male to male inhetitances is not possible for X-linked traits in humans.
In the given case the mother of the son must be a carrier (heterozygous) for colour blindness gune, thus transmiting the gene to her son.