Diatom. Coloured scanning electron micrograph (SEM) of a Bacteriastrum sp. diatom. The diatoms are a group of photosynthetic, single-celled algae containing about 100, 000 species. Magnification: x950 when printed at 10 centimetres wide.

Diatom. Coloured scanning electron micrograph (SEM) of a Rutilaria epsilon diatom. The diatoms are a group of photosynthetic, single-celled algae containing about 100, 000 species. Magnification: x1000 when printed at 10 centimetres wide.

Diatom. Coloured scanning electron micrograph (SEM) of a Eupodiscus sculptus diatom. The diatoms are a group of photosynthetic, single-celled algae containing about 100, 000 species. Magnification: x800 when printed at 10 centimetres wide.

Diatom. Coloured scanning electron micrograph (SEM) of a Triceratium sp. diatom. The diatoms are a group of photosynthetic, single-celled algae containing about 100, 000 species. Magnification: x800 when printed at 10 centimetres wide.

Diatom. Coloured scanning electron micrograph (SEM) of a Campylodiscus fastuosus diatom. The diatoms are a group of photosynthetic, single-celled algae containing about 100, 000 species. Magnification: x1000 when printed at 10 centimetres wide.

Deformed sperm cell. Coloured scanning electron micrograph (SEM) of a sperm cell with multiple tails. Magnification: x5000 when printed at 10 centimetres wide.