If a boy exhibits a sex-linked trait that is carried on the x chromosome, what must be true?
a. his mother exhibited that trait.
b. his father exhibited that trait.
c. his father’s mother carried an allele for that trait.
d. his mother carried at least one allele for that trait.

some fungi obtain their nutrients from a living host (plant or animal) and are called most biotrophic fungi have fairly narrow host ranges—they are specialized on a limited called rhizomorphs that allow the fungus to grow from one tree to another. ascospores are formed inside a sac-like structure called an ascus. so your answer is a