Question

State whether the following statement is true or false.

Sex-linked recessive traits in mammalian populations are always expected to be more frequent in males than in females.

Answer 1

This statement is true.

Explanation:

Sex-linked recessive traits are usually located on the X chromosome. Since males have only one X chromosome (XY), a single recessive allele on that chromosome will express the trait because there is no corresponding allele on the Y chromosome to mask it. Females have two X chromosomes (XX), so a recessive trait would have to be present on both X chromosomes (homozygous recessive) to be expressed. Therefore, these traits appear more frequently in males than in females, who are more often carriers but do not express the trait unless homozygous recessive. This principle is exemplified by traits like red-green color blindness and hemophilia, which are more common in males than females due to this X-linked recessive inheritance pattern.