EgHuman fertilisation. Animation of sperm cell attempting to fertilise an egg cell. Each cell contains one half of the genetic material needed to form a new human. Only one of some 300 million sperm released during ejaculation will fertilise the single egg. Once it has penetrated to the internal areas, rapid chemical changes make the egg's outer layer (zona pellucida) thicken, which prevents any other sperm entering the egg. The nucleus of the successful sperm fuses with the nucleus of the egg to form a zygote, which will develop into an embryo. The first stages of cell division in the zygote are also shown. | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library |
Modell-Rechte: | nicht erforderlich |
Länge: | 25 Sekunden |
Seitenverhältnis: | 16:9 |
Restrictions: | - |