Sickle Cell Anaemia Is a Recessive Trait in Humans

Multiple Choice

Sickle cell anaemia is a recessive trait in humans.The gene that causes this disease is not located on the sex chromosomes.In a cross between a father who has sickle cell anaemia and a mother who is heterozygous for the gene,what is the probability that their first three children will have the normal phenotype?

A) 1/4
B) 1/2
C) none
D) 1/8
E) 1/16 will be albino