問題詳情
18.tWhich of the following best describes double fertilization in flowering plants?
(A)tFlowers must be pollinated twice to yield both fruits and seeds.
(B)tOne sperm fertilizes the egg, and a second sperm fertilizes both polar nuclei.
(C)tThe egg of the embryo sac is diploid.
(D)tTwo sperms are needed to fertilize the egg.
參考答案
答案：99
統計：A:0,B:0,C:0,D:0,E:0
難度：計算中