Early development of an individual from a fertilized egg (zygote). Following cleavage of the zygote, the major axes are established during the blastula stage; in the subsequent gastrula stage, the early embryo invaginates and acquires three cell layers. ( Figure 23-5)
the development and growth of an embryo. Endothermic (also homeothermic or warm-blooded) - having ability to maintain constant body temperature in different ambient temperatures.
Development of an embryo from a fertilized egg, or zygote.