n.胚泡；囊胚
=blastula.
M+B：morula and blastocyst stages. 桑椹期和囊胚期。
The zygote, by cell division, grows into a morula an then into a blastocyst. 通过细胞分裂，受精卵发育成桑葚胚，然后发育成囊胚。
The blastocyst can then be transplanted into a female mouse to develop to term. 胚泡又被移植入母鼠体内生长。
But the blastocyst from which it came can continue to develop into an embryo and then a foetus. 但它是从胚泡移走细胞能继续发展成为一个胚胎,胎。
The researchers used fast neutrons to irradiate mouse embryos between the blastocyst stage and the beginning of somite formation. 研究人员用快中子照射在胚泡期和体节形成开始之间的小鼠胚胎。
囊胚
