Images Dated 30th October 2003

Sickle cell anaemia

Sickle cell anaemia. Artwork of red blood cells in sickle cell anaemia (drepanocytosis). The sickle- shaped red blood cells (some seen at upper left) contrast with normal red blood cells (rounded, one at lower centre). Also seen are platelets (small, blue) and two white blood cell types (granulocyte, centre right; lymphocyte, top centre). Sickle cell anaemia is an inherited blood disease that largely affects black people, in which the red blood cells contain abnormal haemoglobin, the oxygen-carrying pigment. Deoxygenated haemoglobin distorts the red blood cells into a fragile sickle shape, and they are easily destroyed, which causes the lack of red blood cells that leads to symptoms of anaemia

© JOHN BAVOSI/SCIENCE PHOTO LIBRARY

Pussy willow pollen

Willow pollen. Coloured scanning electron micro- graph (SEM) of a pollen grain of goat willow, Salix caprea. Also known as the "pussy willow". This elongated pollen grain has a grooved and pitted surface. It's protein coat is distinctive of the willow genus (Salix). Pollen is produced by the male sex organs in flowers and dispersed to the female sex organ where the egg is fertilized. The protein coat is both highly characteristic and resistant to decay. Thanks to these properties, studies of ancient pollen like willow from deep soil samples has helped to reveal the history of European vegetation since the last ice age. Magnification: x800 at 6x6cm size

© DR JEREMY BURGESS/SCIENCE PHOTO LIBRARY