問題詳情
37. What occurs during gastrulation?
(A) A solid embryo is changed into a hollow morula.
(B) A solid blastula is changed into a hollow embryo with a dorsal nerve cord.
(C) A hollow blastula is changed into a hollow embryo that has three tissue layers.
(D) A neural tube is created by invagination of the ectoderm.
參考答案
答案：[無官方正解]
難度：計算中-1
書單：沒有書單，新增