Genetics

The science of heredity in organisms. The father of modern genetics was Gregor Mendal, an 18th centuary monk, who observed that specific cosmetic traits in the parents are inhereted by the offspring. 'Sues sometimes use this science to create speshul powers, or heratiges for themselves, not realising that it is actually genetically impossible.

Sueish Genetics
Half [insert magical creature]/ half human. Wierd and wonderful eye/hair colours. Sue-per powers, inhereted from a parent.

Charges
Genetic impossibilities or improbabilities is a serious charge for some, more scientifically minded agents. Others may quibble that it is all bad biology.