Question

select the correct answer.
in a family, the father is affected by a genetic disorder. the son in the family has the same disease, but the daughters do not have it. what type of inheritance is this?
a. y - linked
b. x - linked
c. polygenic
d. codominant

Explanation:

To determine the inheritance type, we analyze each option:

• Option A (Y - linked): Y - linked traits are carried on the Y chromosome. Males (who have a Y chromosome) inherit Y - linked traits from their fathers. Since the father has the disorder, the son (who gets the Y from the father) has it, and daughters (who get X chromosomes from the father) do not. This matches the scenario.
• Option B (X - linked): X - linked inheritance can be dominant or recessive. If it were X - linked, daughters could inherit the disorder from their father (as they get an X from him), which does not match the given situation where daughters do not have the disease.
• Option C (polygenic): Polygenic traits are controlled by multiple genes and do not follow the pattern of father - to - son transmission with daughters being unaffected in this way.
• Option D (codominant): Codominance involves both alleles being expressed equally, and it does not have the sex - linked (father - son, daughters unaffected) pattern seen here.

Answer:

A. Y - linked