Mutation is a sudden inheritable variation.
Term given by Hugo de Vries while working on the plant Oenothera lamarckiana (Evening Primrose).
1st experimental evidence on mutation was given by Morgan while working on eye color in Drosophila. White eye color is due to a recessive mutation having occurred on the X-chromosome.
Mutations are of 2 types: – Chromosomal mutations and Gene mutations.
It includes chromosomal aberrations and genomic mutations.
Chromosomal aberrations – change in chromosome structure.
They are 4 types: Deficiency, Duplication, Translocation, and Inversion.
It is the loss of certain genes from a haploid genome. It may be terminal or interstitial. E.g.,
Notched wing in Drosophila is due to deletion of a segment in X-chromosome.
Cri-du-chat syndrome in humans is due to deletion of a part of the short arm of chromosome 5.