During embryogenesis, the separation of cells into the three individual germ layers first occurs during which of the following?

During embryogenesis, the separation of cells into the three individual germ layers first occurs during which of the following?

Formation of the primitive streak occurs during what stage of embryogenesis?

Formation of the primitive streak occurs during what stage of embryogenesis?

Which of the following defines the process by which the entry of one sperm into an oocyte prevents other sperms from fertilizing the same egg?

Which of the following defines the process by which the entry of one sperm into an oocyte prevents other sperms from fertilizing the same egg?

The inner cell mass (or embryoblast) of the blastocyst gives rise to all of the following layers except __________.

The inner cell mass (or embryoblast) of the blastocyst gives rise to all of the following layers except __________.

During gastrulation, the developing embryo undergoes a reorganization of the cells into a multi-layered organism, with each layer necessary to form distinct parts of the eventual fully-formed organism. Which of these primary layers will ultimately form the skin and the nervous system of the organism?

During gastrulation, the developing embryo undergoes a reorganization of the cells into a multi-layered organism, with each layer necessary to form distinct parts of the eventual fully-formed organism. Which of these primary layers will ultimately form the skin and the nervous system of the organism?