Chromosome duplication

Part of a chromosome in duplicate.

A particular kind of mutation involving the production of one or more copies of any piece of DNA, including sometimes a gene or even an entire chromosome.

A duplication is the opposite of a deletion.</P> Duplications have been important in the evolution of the human genome (and the genomes of many other organisms).

Duplications typically arise from an event termed unequal crossing-over (recombination) that occurs between misaligned homologous chromosomes during meiosis (germ cell formation).

The chance of this event happening is a function of the degree of sharing of repetitive elements between two chromosomes.

The recombination products of such an event are a duplication at the site of the exchange and a reciprocal deletion.

A remarkable class of duplications in which the duplicated region has popped up far away from home base has also been discovered.