Explain mutation and its type in detail?
Explain mutation and its type in detail?
Dear student,
In biology,, a mutation is the permanent alteration of thenucleotide sequence of the genome of an organism,virus, or extrachromosomal DNA or other genetic elements.
Mutations in the structure of genes can be classified as Small-scale Mutationsand Large Scale Mutations.
Small-scale mutations are types of gene mutations, such as those affecting a small gene in one or a few nucleotides, including:
- Point mutations
A mutation is said to be punctual when it touches one or more nucleotides of the same gene.
a. Substitution mutations :
- Missense mutations: This point mutation results in the replacement of one nucleotide by another. In some cases, this change causes a change in the amino acid encoded, which may or may not have an impact on the function of the protein produced by the gene in the case of a gene encoding, or the affinity for a transcription factor, in the case of a promoter region of the DNA.
- Nonsense mutation: In this instead of substituting one amino acid for another, however, the altered DNA sequence prematurely signals the cell to stop building a protein. This type of mutation results in a shortened protein that may function improperly or not at all.
- Silent mutations: These are mutations that do not alter the sequence of a protein because of the redundancy of the genetic code (the new triplet codes for the same amino acid as the original triplet), or because it affects an area not coding DNA or an intron.
2.Insertions and deletions
The insertions and deletions are the type of mutations and are the two types of mutations called frame-shift. Addition or deletion of nucleotides is not a multiple of 3 will cause a change of reading frame of the genetic code.
- Insertions add one or more extra nucleotides into the DNA. An insertionchanges the number of DNA bases in a gene by adding a piece of DNA.
- Deletions mean removing one or more nucleotides from the DNA. Like insertions, these mutations can alter the reading frame of the gene.
Large Scale Mutations
1,Chromosomal Mutations
It can be a loss or gain of chromosomes:These mutations change from one generation to the next, they correspond to the high repetition of some triplets at the DNA level
2,Somatic or Germline mutations
We speak of germ-line mutation or de-novo mutation when the mutation involves the DNA of stem cells from a gamete. In this case, the embryo will carry the mutation without any of its parents are possessed in his genetic heritage. This type of mutation occurs during the formation of life or the gametes of one parent (sperm or ovum).
- Generally the somatic mutations do not affect cells for reproduction, they are never inherited:
Hope you iunderstood
Regards
Dear student,
In biology,, a mutation is the permanent alteration of thenucleotide sequence of the genome of an organism,virus, or extrachromosomal DNA or other genetic elements.
Mutations in the structure of genes can be classified as Small-scale Mutationsand Large Scale Mutations.
Small-scale mutations are types of gene mutations, such as those affecting a small gene in one or a few nucleotides, including:
- Point mutations
A mutation is said to be punctual when it touches one or more nucleotides of the same gene.
a. Substitution mutations :
- Missense mutations: This point mutation results in the replacement of one nucleotide by another. In some cases, this change causes a change in the amino acid encoded, which may or may not have an impact on the function of the protein produced by the gene in the case of a gene encoding, or the affinity for a transcription factor, in the case of a promoter region of the DNA.
- Nonsense mutation: In this instead of substituting one amino acid for another, however, the altered DNA sequence prematurely signals the cell to stop building a protein. This type of mutation results in a shortened protein that may function improperly or not at all.
- Silent mutations: These are mutations that do not alter the sequence of a protein because of the redundancy of the genetic code (the new triplet codes for the same amino acid as the original triplet), or because it affects an area not coding DNA or an intron.
2.Insertions and deletions
The insertions and deletions are the type of mutations and are the two types of mutations called frame-shift. Addition or deletion of nucleotides is not a multiple of 3 will cause a change of reading frame of the genetic code.
- Insertions add one or more extra nucleotides into the DNA. An insertionchanges the number of DNA bases in a gene by adding a piece of DNA.
- Deletions mean removing one or more nucleotides from the DNA. Like insertions, these mutations can alter the reading frame of the gene.
Large Scale Mutations
1,Chromosomal Mutations
It can be a loss or gain of chromosomes:These mutations change from one generation to the next, they correspond to the high repetition of some triplets at the DNA level
2,Somatic or Germline mutations
We speak of germ-line mutation or de-novo mutation when the mutation involves the DNA of stem cells from a gamete. In this case, the embryo will carry the mutation without any of its parents are possessed in his genetic heritage. This type of mutation occurs during the formation of life or the gametes of one parent (sperm or ovum).
- Generally the somatic mutations do not affect cells for reproduction, they are never inherited:
Hope you iunderstood
Regards
