An example of gene therapy is

Which of the following is/are correct about Adenosine Deaminase $(ADA)$ deficiency?
$I$. In the absence of adenosine deaminase enzyme,purine metabolism is disturbed and $T$-lymphocytes fail to function.
$II$. $ADA$ deficiency is caused by the deletion of the gene for $ADA$.
$III$. In some cases,it can be cured by bone marrow transplantation and enzyme replacement therapy. But in both approaches,the patients are not completely cured.
$IV$. For permanent cure,genes isolated from the bone marrow cells producing $ADA$ at early embryonic stages can be a possible cure.
Which of the above statements are correct?

Magic bullets are the

The two polypeptide chains of human insulin are linked together by which of the following?

At present,about ........ recombinant therapeutics have been approved for human use the world over. Out of these,........ are being marketed in India.

The $C$-peptide is .......