Reference no: EM132436085

Question 1: The gene for yellow body color (b) in fruit flies is X-linked recessive. Its dominant allele (B) produces normal body color. What is the phenotypic ratio of the offspring that results from a cross between:

• a yellow male and yellow female?
• a yellow female and normal colored male?
• a homozygous normal female and yellow male?
• a normal heterozygous female and normal male?

Question 2: A form of hemophilia in humans is caused by the presence of an X-linked recessive allele (-), whose normal non-hemophiliac gene is (+).

• Can two hemophiliac parents produce a normal son? A normal daughter?
• Can two normal parents produce a hemophiliac son? A hemophiliac daughter?
• Can a hemophiliac brother and sister have another sister who is normal?