知识贝壳
知识贝壳
所属栏目：英汉双解生物学
A membrane-bound structure inthe anterior head region of a spermatozoon,usually forming a cap over the nucleus. Itcontains enzymes that are released on contactwith the egg at fertilization and break downthe egg coats,enabling the spermatozoon nu-cleus to ......（本文共 296 字 ） [阅读本文] >>