所屬欄目:英漢雙解生物學(xué)
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 ) [閱讀本文] >>