常見例句Any of the blastomeres from which the ectoderm develops. 外裂球任一種發(fā)育成外胚層的裂球An inward fold on the surface of the embryonic ectoderm that develops into part of the anal passage. 原肛肛道胚胎消化道表麪的凹陷,發(fā)育成直腸的一部分Derived from two embryonic germ layers, the ectoderm and the endoderm. Used of lower invertebrates, such as sponges and coelenterates. 雙胚層的具有兩個胚層(外胚層和內胚層)的。用於低等無脊椎動物,如寄生蟲和腔腸動物The resulting gastrula consists of an outer ectoderm, an inner endoderm, and a mesoderm layer positioned between them. 最終原腸胚由一個外腸胚,內腸胚,和一個中腸胚搆成。The primitie mouth, or stomodeum, is a slight depression on the surface of the ectoderm. 原始的口(或口凹)是外胚層表麪的一個輕微的凹陷。The outer layer of a blastula that gives rise to the ectoderm after gastrulation. 外胚層囊胚的外層,在原腸胚形成之後生後外胚層組織 返回 ectoderm