The production of human proteins in bacteria through genetic engineering is possible because

Which of the following bacteria is a close relative of $Salmonella$?

Assertion : In recombinant $DNA$ technology,human genes are often transferred into bacteria (prokaryotes) or yeast (eukaryote).
Reason : Both bacteria and yeast multiply very fast to form huge population,which express the desired gene.

Which of these is widely used in genetic engineering?

Consider the following statements:
$I.$ Recombinant $DNA$ technology,popularly known as genetic engineering,is a stream of biotechnology which deals with the manipulation of genetic material by man in vitro.
$II.$ $pBR322$ is the first artificial cloning vector developed in $1977$ by Bolivar and Rodriguez from $E. coli$ plasmid.
$III.$ Restriction enzymes belong to a class of enzymes called nucleases.
Which of the statements given above are correct?

Give differences between $PCR$ and plasmid.