Answer to Question #25607 in Molecular Biology for raghav

Question

define mutation and its types

Answer 1

A mutation is a permanent change in the DNA sequence of agene.There are many different ways that DNA can be changed,resulting in different types of mutation. Here is a quick summary of a few of these:
- A substitution is a mutation that exchanges one basefor another (i.e., a change in a single "chemical letter" such as
switching an A to a G).
- Insertions are mutations in which extra base pairs areinserted into a new place in the DNA.
- Deletions are mutations in which a section of DNA islost, or deleted.
- Duplication consists of a piece of DNA that isabnormally copied one or more times. This type of mutation may alter the
function of the resulting protein.
- Frameshift - since protein-coding DNA is divided intocodons three bases long, insertions and deletions can alter a gene so that its
message is no longer correctly parsed.
- The repeat expansion is a mutation that increases thenumber of times that the short DNA sequence is repeated.