What is point mutation? Give one example.

(N/A) Point mutation is a genetic mutation that involves a change in a single base pair of $DNA$ through substitution,deletion,or insertion of a single nitrogenous base.
An example of point mutation is sickle cell anaemia.
It involves a mutation in a single base pair in the $\beta$-globin chain of the haemoglobin pigment in the blood.
Specifically,the codon for glutamic acid is replaced by the codon for valine at the sixth position in the $\beta$-globin chain,which is encoded by a gene on chromosome $11$.