详细解释:n. 囊胚
词型变化：
名词:blastulation名词复数:blastulas形容词:blastular英语解释：
名词 blastula:
early stage of an embryo produced by cleavage of an ovum; a liquid-filled sphere whose wall is composed of a single layer of cells; during this stage (about eight days after fertilization) implantation in the wall of the uterus occurs同义词：blastodermic vesicle