zygote is an egg and sperm

fertilization ovum egg cell embryo development zygote vector pregnancy biology sperm ovule morula blastula 4cell anatomy gastrula blastomeres embryonic cage child birth cytoplasm division embryology endoderm female fertility fetus follicle genes gynecology health human infertility insemination medical medicine microscopic natural oocyte ovary ovulation penetrate reproduction reproductive seed stage fertilized treatment fertilization sperm segmentation ovum embryo vector