Biology - Variation due to genetic differences
Variation due to genetic differences
Skin colour, resulting from several genes, is said to be polygenic.
Structural variation is obvious in domestic animals that have been bred
for particular traits
A population is said to be polymorphic for a trait if there are several
variants for that particular trait for example the coat colour of tabby
cats, human blood groups. If the population is identical for a particular
trait, that is no variations for that trait, it is said to be monomorphic
 for that trait. If the characteristic is controlled by one gene it is
said to be monogenic,  if the result of several genes, for example,
human skin colour, then it is polygenic.  Variation in chromosome number
within a species also contributes to variations, for example, polyploidy in
thorn apples gives rise to differences in fruit shape and texture between
members of the same species.
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