Circulatory system, by LadyofHats (edited by Jinman11)

Spider anatomy, by Pbroks13 (edited by ZooFari, and Kaldari)

Steroidogenesis, by Mikael Häggström et al

Triosephosphate isomerase ribbon diagram, at and by Jane S. Richardson (Dcrjsr)

Herring Gull excreting waste from its cloaca, by Sanchezn

Human arm bones, by LadyofHats

Wormian bones, by LadyofHats

Human respiratory system, by LadyofHats

Autotomy, by Fir0002

Citric acid cycle, by YassineMrabet (edited by Narayanese, TotoBaggins)

Female human skeleton (back view), by LadyofHats

Female human skeleton (front view), by LadyofHats

Neuron cell diagram at Dendrite & Chemical synapse, by LadyofHats

Diagram of an eye, by Chabacano

Osmotic pressure on blood cells at Osmosis, by LadyofHats

Strabismus surgery, by Bticho

Embryo by Ed Uthman

DNA clamp, by Opabinia regalis

Antarctic krill eye at Compound eye, by Uwe Kils

Root canal, by Jeremykemp, traced by jellocube27

Polydactyly, by Drgnu23

Diagram summarising control of stomach acid secretion at Gastric acid and Stomach, by Prisonblues

Three cell division types at Cell growth, by JWSchmidt

Antigenic shift, by National Institute of Allergy and Infectious Diseases

Pharyngeal jaws, by Zina Deretsky, US National Science Foundation (SVG version by Pbroks13)

Tree of life (science), by Ernst Haeckel (edited by Ragesoss)

Studies of Embryos by Leonardo da Vinci (photographed by Luc Viatour)

The Vitruvian Man, by Leonardo da Vinci (photographed by Luc Viatour)

Agar plate containing infected blood, by Bill Branson (edited by Fir0002)

Neutrophil engulfing anthrax bacterium, by Volker Brinkmann

Volume rendering of a rat skull, by Lackas

Magnetic resonance imaging, by Fastfission