Question

the pedigree below is illustrating a sex - linked recessive trait. what is the phenotype of individual ii - 2?
pedigree 7. x - linked recessive inheritance
normal
carrier
affected

Explanation:

1. The pedigree shows a sex - linked recessive (X - linked recessive) trait.
2. Individual II - 2 is a female. Her son (III - 2) is affected (has the X - linked recessive trait). For an X - linked recessive trait, an affected son gets the recessive allele from his mother.
3. Since the son is affected (has the recessive allele on his X chromosome from the mother), the mother (II - 2) must be a carrier. She has one normal X and one X with the recessive allele, so her phenotype is a carrier (she doesn't show the disease phenotype but can pass the allele).

Answer:

carrier