試題詳解

9. A black guinea pig crossed with a guinea pig with albinism produced 12 black offspring. When the albino was crossed with a second black animal, six blacks and six albinos were obtained. What is the best explanation for this genetic situation?
(A) Albinism is a recessive trait； black is a dominant trait.
(B) Albinism is a recessive trait； black is codominant
(C) Albinism and black are codominant.
(D)Albinism is a dominant trait； black is incompletely dominant.