Bee stinger. Coloured scanning electron micrograph (SEM) of the end of the abdomen of a small tropical bee, showing the barbed stinger (needle-like). The stinger is used to inject venom when the bee feels threatened. Unlike wasps, bee stingers have barbs which prevent the bee from pulling them out. Instead, the stinger stays in the victims skin and is ripped out of the bee's body, killing the bee. Magnification x70 when printed 10 centimetres wide.
dental floss (fio dental)
Anticoncepcional Masculino em Gel apresenta bons resultados em pesquisa
A grain of wheat
Agulha e linha
Human chromosomes and nucleus, coloured scanning electron micrograph (SEM). Chromosomes are a packaged form of the genetic material DNA (deoxyribonucleic acid). The DNA normally exists in a non-condensed form in the cell nucleus (upper right). It condenses into chromosomes (centre and lower left) during cell replication. In humans, there are 46 chromosomes, consisting of 23 chromosome pairs. Magnification: x4350 when printed at 10 centimetres across.