Question

why would a nephew resemble his biological uncle?
the nephew contributed half of his genetic makeup to the uncle.
the grandparents passed similar dna to the uncle and the boy’s father; the father then passed the similar dna on to his son (i.e., the nephew).
half of the nephew’s genetic makeup came from his uncle.
the grandparents passed similar dna to the uncle and the nephew.

Explanation:

Genetic similarity between a nephew and uncle arises from shared grandparents. The uncle inherits DNA from the grandparents, and the nephew's father (the uncle's sibling) also inherits similar DNA from the same grandparents. The father then passes this shared DNA to the nephew, leading to resemblance. Other options are incorrect: the nephew does not contribute DNA to the uncle, does not get half his DNA from the uncle, and the grandparents do not pass DNA directly to both the uncle and nephew (the nephew gets DNA from his father, who got it from the grandparents).

Answer:

B. The grandparents passed similar DNA to the uncle and the boy's father; the father then passed the similar DNA on to his son (i.e., the nephew).