Embroyo develops from -

Ans. is 'a' i.e., Inner cell mass * As the morula enters the uterine cavity, uterine fluid diffuses through zona pellucida and fills small intercellular gaps between blastomeres, and morula is converted to blastocyst. Blastocyst consists ofa) Zona pellucida: Outer covering.b) Embryoblast: A group of centerally located cells of inner cell mass and later give rise to tissues of embryo proper.c) Trophoblast: A thin outer layer of cells formed from outer cells mass and later give rise extraembryonic tissues.d) Blastocele: Cavity of blastocyst: