Question

Sex-linked conditions are more common in men than in women because

A) the sex chromosomes are more active in men than in women.
B)men need to inherit only one copy of the recessive allele for the condition to be fully
expressed.
C) the genes associated with the sex-linked conditions are linked to the Y chromosome, which
determines maleness.
D) men acquire two copies of the defective gene during fertilization.

Answer 1

X-linked recessive traits are more common in men because they have only one X chromosome and need to inherit only one copy of the recessive allele for the condition to be fully expressed.

Step-by-step explanation:

X-linked recessive traits, such as red-green color blindness and hemophilia, are more common in men than in women due to the fact that males have only one X chromosome, while females have two. This means that males need to inherit only one copy of the recessive allele for the condition to be fully expressed, whereas females must inherit two copies.

As a result, X-linked recessive disorders are disproportionately observed in males. For example, color blindness affects approximately 1 in 20 males but only about 1 in 400 females.