Question

What is gene mutation? Describe the types of gene mutation.

Answer 1

Gene or point mutation is a sudden change in the small segment of DNA either a single nucleotide or nucleotide pair. It may be caused by loss or deletion of a nucleotide pair is called deletion. For example, bacteriophages.
The addition of one or more nucleotides into a gene results in addition mutation. Replacement of certain nitrogen base by another base in DNA is the substitution.
Types of Substitution:
a) Transition: When a purine (A or G) or a pyrimidine (C, U or T) is replaced by another purine or pyrimidine respectively.
b) Transversion: When a mutation involves the replacement of purine. (A & G) for pyrimidine (C, U and T) or vice versa.