Biology 2581B Study Guide - Quiz Guide: Polarity In Embryogenesis, Blastula, Blastocoel
1 Jun 2020
School
Department
Course
Professor
Document Summary
Early in embryogenesis a blastula forms and all cells in it are pretty much the same. They may be a little smaller on top (animal pole) and a little bigger on the bottom (vegetal pole), but they haven"t differentiated yet. A massive amount of cell movement occurs to take animals from this ball of cells to the correct shape. At this early stage, three germ layers form - ectoderm, endoderm and mesoderm - which gives rise to very specific tissues in the fully formed body. These germ layers then get rearranged to suit their future purpose. Ectoderm gives rise to neurons, glia (support cells for neurons), neural crest cells, placodes (ears and eyes) and epidermis mesoderm gives rise to muscle, cartilage, bone, dermis, kidney, heart and blood. Endoderm gives rise to the gut and associated organs as well as yolk cells. Gastrulation is the process of the embryo changing from a blastula to a gastrula.
