Biochemistry
From Tardis Wiki, the free Doctor Who reference
Ghosties had a different blood biochemistry to humans. (AUDIO: Asylum)
According to the Seventh Doctor, the pH of the blood gave an idea of a species' basic biochemistry. (AUDIO: A Thousand Tiny Wings)
Elkinar was a doctor of biochemistry and applied xeno-agronomy. (AUDIO: The Seeds of War)
Hex noted that the Seventh Doctor had a different biochemistry to humans, and therefore using chloroform on him consistently was not having the "right" effect. (AUDIO: The Magic Mousetrap)
