(i) Heredity is the transfer of biological characters from one generation to another via genes.
(ii) Living organisms can produce new individuals like themselves due to genes only and some of those genes are transmitted to the most generation without any changes.
(iii) Due to this, some of the characters of parents are transmitted to their offsprings.
(iv) However, sometimes sudden changes occur in those genes.
(v) Sometimes any nucleotide of the gene changes its position and that causes a minor change which is called as mutation.
(vi) Some mutations maybe minor but some may be considerable.
E.g. Mutation may cause the genetic disorder like sickle cell anaemia.
