From Zygote to Blastocyst Stem Cells

Zygote development shows how a fertilized egg becomes the first stages of a new organism. When sperm and egg fuse, they form a diploid zygote. A zygote is totipotent, which means it can develop into a complete organism.

The zygote then divides by cleavage to form an 8-cell mass. At this stage, th...

All multicellular organisms arise from a single fertilized egg cell called the zygote. The zygote divides mitotically to form an eight-cell mass.

At this stage, the cells are called totipotent stem cells that can reproduce, renew, and specialize into different tissues upon implantation.

The dividing stem cells form a 64-cell mass c...