Although scientists once theorized that all embryos start developing as females, recent research suggests that neither sex is "default." Legal experts told PolitiFact they see no basis for the claim ...

In the mouse developing embryo, she previously demonstrated a bias at the two ... fused to a membrane trafficking sequence into one of the two cells of the zygote. Thus, they could determine the ...

"The zygote is a single cell and contains the genetic blueprint to direct the next complex steps to become the embryo and fetus," says What to Expect Medical Review Board Member Aaron K.

This produces a new cell called a zygote, which will mature into an embryo. The number of cells increase by mitosis, and as the embryo develops, the cells begin to differentiate (or specialise).

The fusion of sperm and egg gametes during human fertilization establishes a diploid zygote and initiates a series of cell divisions that result in a multicellular embryo. The blastocyst stage is ...