The name of the drug used in cancer treatment produced by biotechnology is:

Correct chronological order of the steps occurring during gene therapy are
$I$. Lymphocytes are obtained from the patients
$II$. Lymphocytes are transferred to the culture dishes
$III$. Lymphocytes are transfected with the normal $ADA$ genes
$IV$. The transfected cells are returned to the patients
The chronological order should be

An example of gene therapy is

Consult internet and find out how to make orally active protein pharmaceutical. What is the major problem to be encountered?

Which one of the following genes is defective in patients suffering from Severe Combined Immunodeficiency Disease $(SCID)$?

Many proteins are secreted in their inactive form. This is also true of many toxic proteins produced by microorganisms. Explain how this mechanism is useful for the organism producing the toxin?