Hepatitis $B$ vaccine is produced by.......

In the processing of proinsulin into mature insulin,which of the following steps occurs?

Human insulin is being commercially produced from a transgenic species of

Which of the following is used as a vector in gene therapy?

Maturation of proinsulin into insulin takes place after

Find the correct statements from the following:
$I.$ Gene therapy is a genetic engineering technique used to treat diseases at the molecular level.
$II.$ Calcitonin is a medically useful recombinant product in the treatment of infertility.
$III.$ Bt toxin is a biodegradable insecticide obtained from $Bacillus \text{ } thuringiensis$.