One of the applications of biotechnology is 'gene therapy" to treat a person born with a hereditary disease.
(i) What does "gene therapy " mean ?

Explanation

(i) Gene therapy is the process in which the defective genes are replaced with normal genes leading to the expression of proper phenotype.
(ii) SCID (Severe Combined Immuno Deficiency) disease was the first disease treated by using gene therapy.
(iii) There are two strategies involved in gene therapy namely, Gene augmentation therapy, which involves insertion of DNA into the genome to replace the missing gene product, and Gene inhibition therapy, which involves insertion of the anti sense gene which inhibits the expression of the dominant gene.