The enzymes commonly used in genetic engineering are:

$A$ plasmid $DNA$ and a linear $DNA$ (both are of the same size) have one site for a restriction endonuclease. When cut and separated on agarose gel electrophoresis,the plasmid shows one $DNA$ band while the linear $DNA$ shows two fragments. Explain.

Common bacteria used in genetic engineering is

Which of the following statements are not true regarding restriction endonucleases?
$A$. They are called molecular scissors.
$B$. These are the enzymes responsible for restricting the growth of bacteriophages in $E. coli$.
$C$. They cut the $DNA$ only at the centre of the palindromic sites.
$D$. They remove nucleotides only from the ends of $DNA$ fragments.
$E$. They recognise specific palindromic base-pair sequences.
Choose the answer from the options given below:

$c-DNA$ can be formed by

Which statement is correct regarding the $DNA$ polymerase used in $PCR$?