Which of the following is a genetic disease

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

Study the pedigree chart of a certain family given below and select the correct conclusion which can be drawn for the character.

If a colour­blind man marries a woman who is homozygous for normal colour vision, the probability of their son being colour­blind is

Given below is a pedigree chart showing the inheritance of a certain sex- linked trait in humans.

The trait traced in the above pedigree chart is