What is point mutation? Give an example.

Point mutation:

Point mutation refers to a change in one or few nucleotides in the DNA.

The different types of point mutations are:

1. Substitution: One nucleotide is replaced by another nucleotide.
2. Insertion: An extra nucleotide is inserted into the sequence.
3. Deletion: A nucleotide is deleted from the sequence.

Examples of point mutations:

1. Cystic fibrosis is caused by the deletion of three nucleotides in the CFTR gene.
2. Sickle cell anemia is caused by a single substitution wherein a glutamic acid is replaced by valine.