blastosphere n 1: 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 [syn: {blastula}, {blastosphere}]
Morula \Mor"u*la\, n.; pl. {Morulae}. [NL., dim. of L. morum a mulberry.] (Biol.) The sphere or globular mass of cells (blastomeres), formed by the clevage of the ovum or egg in the first stages of its development; -- called also {mulberry mass}, {segmentation sphere}, and {blastosphere}. See {Segmentation}. [1913 Webster]
Blastosphere \Blas"to*sphere\, n. [Gr. blasto`s sprout + E. sphere.] (Biol.) The hollow globe or sphere formed by the arrangement of the blastomeres on the periphery of an impregnated ovum. Note: [See Illust. of {Invagination}.] [1913 Webster]