3. If a daughter has an X-linked recessive disorder, such as color-blindness, she inherited the

trait from

a. her mother

b. her father

c. both parents

d. neither parents

She inherited the trait from C: both parents.

Explanation:

The daughter, being female, has the chromosomes XX. Since the disorder is recessive, both of the chromosomes need to have the disorder's allele in order for it to activate. The daughter's chromosomes can be labeled as X (c) X (c); where the c stands for the color-blindness allele. She needs one X chromosome from the father, and one X chromosome from the mother. Both of these chromosomes contained the (c) allele, as said before, so the mother has one X (c) and the father has one X (c). This means that she inherited the trait from both parents. The final answer is C.