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BIOLOGIE BEFRUCHTUNG
Fertilization. Image 1 of 2. Computer artwork of a sperm cell (centre left) about to penetrate an egg cell (round). Each cell contains one half of the genetic material needed to form a new human. The sperm is from a male and the egg from a female. Only one of some 300 million sperm released during ejaculation will fertilise the single egg. Once it has penetrated, rapid chemical changes make the egg's outer layer (zona pellucida) thicken, which prevents any other sperm entering the egg. The head of the successful sperm releases its genetic material to mix with the egg's genetic material. (KEYSTONE/SCIENCE PHOTO LIBRARY/Christian Darkin) === ===
Instructions
COPYRIGHTPFLICHTIG
License
Rights Managed
Date created
20040323
Place
Credit
KEYSTONE
Source
SCIENCE PHOTO LIBRARY SPL
Byline
CHRISTIAN DARKIN
Size
5500 x 3153 px
File type
JPEG