Question

What kind of gene mutations are possible?

Answer 1

Mutations:

1. Genes are units of heredity. A change in a gene is referred to as a mutation.
2. Gene mutations can cause a permanent change in genes.
3. It causes alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA.
4. Mutations can occur as a result of errors in DNA replication during cell division, exposure to mutagens, or a viral infection.
5. Mutations can occur without a change in the amino acid sequence of the encoded protein. They are known as silent mutations.
6. Other kinds of mutation cause abnormal changes in nucleic acid sequences. Some of these may be harmful while some introduce new alleles and increase the population's genetic variation.
7. Three kinds of gene mutations are possible. They are:

• Base substitutions:

1. These are also known as base mutations.
2. They are single base mutations that can be silent, nonsense, or missense.
3. Base mutations are the simplest type of gene-level mutation which happens when nucleotides are swapped.
4. Substitution of base results in DNA of the same length. Addition nor subtraction of nucleotide takes place.

• Deletions:

1. These happen when frameshift occurs as a result of the deletion of the base.
2. Deletions result in the loss of one or more nucleotides from a segment of DNA. It may include the loss of a single nucleotide or an entire piece of a chromosome.
3. It results in alteration of function of affected proteins.
4. It occurs if a portion of a DNA molecule is not copied during DNA replication

• Insertion:

1. When new base pairs are added to the gene insertion occurs.
2. It involves the addition of single pair of nucleotides to a segment of a chromosome.
3. Insertion of a single base pair can lead to frameshift.
4. Insertion of three base pairs does not result in frameshift but is more harmful than the insertion of just one base pair.