Red-green Color Blindness and Hemophilia A are both sex-linked traits in humans. Both genes are on the X-chromosome and are tightly linked.

Question

Consider the pedigree below. Individual 1 is homozygous normal. Individual 2 is both red-green color blind and a hemophiliac. Individual 6 is the as yet unborn son of 4 and 5.
What is the probability that their son, 6, will be both color blind and a hemophiliac? Express your answer as a number between 0.0 and 1.0. You may use as many significant figures as necessary.

Answer 1

You tell about individuals 1 and 2, but not 4 and 5. Who are 4 and 5?

For 1 and 2, is the person with the recessive colorblindness and hemophilia male or female? If male, none of sons will be either, since they only get the Y-chromosome from him. If female, all the sons will have both, since she has to be homozygous for the recessive genes.

Answer 2

0.5

Answer 3

Traits like human height and skin color shows a wide range of phenotypes, as opposed to just two ot three. From the standpoints of genese and alleles, explain why is this so.