Animal Model
A laboratory animal useful for medical research because it has specific characteristics that resemble a human disease or disorder. Scientists can create animal models, usually laboratory mice, by transferring new genes into them.
Aphelion
The point on a planet's elliptical orbit at which it is furthest from the Sun.
Heteroplasmon
A cell containing a mixture of genetically different cytoplasms, generally different mitochondria or different chloroplasts.