7.3

Question 1

X-linked traits are expressed mainly in males. Why?

Answer 1

Males carry only one X chromosome

Question 2

Females carrying an X-linked recessive trait may not express the trait. Why?

Answer 2

Females carry 2 X chromosomes, one could mask the recessive trait.

Question 3

If a trait is passed from father to son and never observed in females it is likely to be _____

Answer 3

Y-linked