A zygote is the union of a sperm and egg cell. It contains all the genetic information needed to form a human being, with half of the information originating from the egg and half from the sperm. The zygote travels down the fallopian tube and divides to become a blastocyst and eventually an embryo.
In Our Own Words
A zygote is a fertilized egg. It forms when a single sperm enters the mother’s egg cell. It contains all the DNA or genetic information necessary to form a baby. Half the information is from the mother and the other half from the father.