The diagram below shows:

In $1983$,Eli Lilly,an American company,first prepared two $DNA$ sequences corresponding to $A$ and $B$-chains of human insulin and introduced them into the plasmids of $Escherichia$ $coli$ to produce insulin chains. Chains $A$ and $B$ were prepared separately,extracted,and combined by creating:

Which of the following is produced using $E. coli$?

Humulin is

The chemical structure of human insulin was studied by .........

Which of the following statements are false?
$I$. Insulin for curing diabetes,used to be extracted from the pancreas of slaughtered pig and cattle.
$II$. Animal insulin is slightly different from human insulin.
$III$. Animal insulin causes some undesirable side effects such as allergy.
$IV$. Bacteria cannot be made to synthesise insulin from its gene because of the presence of introns.
Choose the correct option.