試題詳解

15. Black fur in mice
(B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What fraction of the progeny of the cross BbTt × BBtt will have black fur and long tails?
(A) 1/16
(B) 1/4
(C) 3/8
(D) 1/3
(E)1/2