Images Dated 12th November 2003

Hair root, SEM

Hair root. Coloured scanning electron micrograph (SEM) of the root (red) and part of the shaft (yellow) of a human hair. The base of the hair is known as the hair bulb and is the site of hair growth. It is usually located in a hair follicle in the skin, at the base of which is an area called the dermal papilla. This region is supplied with blood, which gives nourishment for the production of new hair. As new cells form in the follicle they die, become keratinized and pigmented, and get pushed out to form the shaft of the hair. Magnification: x130 when printed 10cm high

© STEVE GSCHMEISSNER/SCIENCE PHOTO LIBRARY

Computer artwork depicting embryo paternity test

Embryo paternity testing. Computer artwork of a paternity test of an embryo (at upper right). A sample of DNA, deoxyribonucleic acid (orange & red strand), is taken from the embryo and its parents. The genetic code formed from the four bases (at bottom right) on this DNA is revealed by a process called electrophoresis. The DNA bands are transfe- rred onto an autoradiograph (white sheet) for comparison. The embryo's DNA comes partly from each parent as the father's sperm fertilizes the mother's egg (top left). Therefore any of the embryo's DNA bands, or genetic markers (blue rectangles, lower left), which do not match those of its mother must match those of its father

© LAGUNA DESIGN/SCIENCE PHOTO LIBRARY