Explain Mutation and Its Type in Detail?

By K Balaji|Updated : November 9th, 2022

Mutation is the permanent alteration of the nucleotide sequence of the genome of an virus, organism, or extrachromosomal DNA or other genetic elements in Biology.

Types of Mutations

In the structure of genes, mutations can be differentiated as Small-scale Mutations and Large Scale Mutations.

Small-scale Mutations

Gene mutations that impact only one or a few nucleotides in a tiny gene are known as small-scale mutations. Examples include:

Point mutations

When a mutation affects one or more nucleotides in the same gene, it is considered to be punctual.

Substitution Mutations

Missense mutations: A nucleotide is changed by another as a result of this point mutation. In some circumstances, this alteration results in a change in the amino acid encoded, which may or may not affect the function of the protein generated by the gene in the case of a gene encoding change or the affinity for a transcription factor in the case of a promoter region of the DNA.
Nonsense mutation: In this case, the changed DNA sequence prematurely instructs the cell to stop producing proteins rather than replacing one amino acid for another. A truncated protein produced by this kind of mutation may operate incorrectly or not at all.
Silent mutations: Due to genetic code redundancy (the new triplet codes for the same amino acid as the original triplet), or because the mutation affects non-coding DNA or an intron, these mutations do not change the sequence of a protein.

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Insertions and Deletions

The two types of mutations known as frame-shifts are insertions and deletions, which are the type of mutations. A change in the reading frame of the genetic code will result from the addition or deletion of nucleotides that are not multiples of 3.

Insertions change the DNA by introducing one or more additional nucleotides. By include a new piece of DNA, an insertion modifies the number of DNA bases in a gene.
Deletions refer to the removal of one or more DNA nucleotides. These mutations can change the gene's reading frame similarly to insertions.

Large Scale Mutations

Chromosomal Mutations

Chromosomes may be lost or gained as a result: These mutations, which vary from generation to generation and are related to some triplets' high DNA repetition,

Somatic or Germline mutations

When the DNA of stem cells from a gamete is mutated, we refer to this as germ-line mutation or de-novo mutation. In this instance, the embryo will have the mutation even though none of the parents are genetically related to it. This kind of mutation develops in either the gametes of one parent or throughout the process of life (sperm or ovum).

Typically, somatic mutations have little effect on cells' ability to procreate and are never inherited.

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