Fertilisation, illustration. Sperm cell fertilising an egg cell. Women usually release one egg per month, whereas men release millions of sperm in each ejaculation. Only one of these sperm can penetrate the egg's thick outer layer, the zona pellucida, and fertilise it. Fertilisation occurs when the sperm's genetic material (deoxyribonucleic acid, DNA) fuses with the egg's DNA. When this occurs the egg forms a barrier to other sperm. | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Ella Maru Studio |
Bildgröße: | 5912 px × 5912 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |