Click here to learn how a tiny embryo grows into a baby .

"Now those embryos are growing, developing into children," Elliena said.

But the cytoplasm of an egg contains more than just proteins to help an embryo grow.

Some animals, mostly mammals, keep the zygote inside their body where the embryo grows until it is ready to be born.

In about five days the embryo would grow into what is a called a blastocyst, from which stem cells could be extracted.

The company failed - its embryos never grew or developed anywhere near a point where they would contain stem cells.

He swept his farsight across them all, happy to confirm the embryos were growing satisfactorily.

It determines whether a human embryo will grow into a male or a female.

As a scientific control, they let other embryos grow without any injections.

As a result, the brain is compressed as the embryo grows.