Question

What is mutation?

Answer 1

Mutation generally means "change".
In biology, mutation refers to the spontaneous change in DNA gene which consequently alters the genetic message carried by that gene.

Explanation:

Example:
Sickle cell anemia is caused by the displacement of only one amino acid in second `beta`-chain of hemoglobin(oxygen carrying protein). In this case, amino acid, glutamic acid changes into valine at position 6 from N terminal end in hemoglobin `beta`-chain. Thus, it alters the tertiary structure of hemoglobin molecule diminishing its ability to carry oxygen.

Some points to be remembered:

• Mutations in the somatic cells do not pass to offsprings. So they are not of evolutionary importance.
• Mutations in the germ cell pass to new generation. So, they provide raw material for natural selection.

Hope it helps...