Zygote Page 28
A zygote is the name of the egg of a female mammal which has been fertilized by a male sperm. After fertilization the egg and the sperm form a single cell which then begins dividing. The fertilized egg contains all of the genes of both parents. The zygote contains all of the genetic information necessary to produce an organism that resembles its parents. After about four to five weeks the zygote starts to become an embryo. About the 8th week the embryo becomes a fetus and after 39 or 40 weeks the fetus becomes a baby when it is born. Embryo is one of the stages of pregnancy. The fetus stage comes after the embryo stage.