Question

the pedigree on the right shows the inheritance pattern for an x - linked recessive disorder. how many individuals are carriers of the disease but are not affected?

Explanation:

Step1: Understand X - linked recessive inheritance

In X - linked recessive disorders, females (XX) can be carriers (heterozygous, one normal X and one mutant X) and not affected. Males (XY) can either be affected (mutant X) or normal (normal X), they cannot be carriers.

Step2: Identify carrier females in the pedigree

Looking at the pedigree, the half - filled circles (females) represent carriers. Count them.

Answer:

4