bild
BEFRUCHTUNG EIZELLE
Fertilisation. Coloured light micrograph of a sperm cell (spermatozoan, right) swimming towards a human egg (ovum, centre). The sperm has a rounded head and a long tail with which it swims. 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. Magnification: x625 when printed at 10 centimetres wide. (KEYSTONE/SCIENCE PHOTO LIBRARY/AJ PHOTO)
Instruktionen
COPYRIGHTPFLICHTIG
Lizenz
Rights Managed
Erstellungsdatum
02-May-07
Ort
Credit
KEYSTONE
Source
SCIENCE PHOTO LIBRARY SPL
Byline
AJ PHOTO
Grösse
3666 x 2500 px
Dateityp
JPEG
MENSCH KUENSTLICHE BEFRUCHTUNG EIZELLE
MOTTA AND FAMILIARI / ANATOMY DEPT. / UNIVERSITY, "LA SAPIENZA", ROME
14031255