The ligation of an antibiotic resistance gene with a plasmid vector can be performed by which of the following enzymes?

Manipulation of $DNA$ in genetic engineering became possible due to the discovery of

Given below are two statements:
Statement $I:$
Restriction endonucleases recognise specific sequences to cut $DNA$,known as palindromic nucleotide sequences.
Statement $II:$
Restriction endonucleases cut the $DNA$ strand a little away from the centre of the palindromic site.
In the light of the above statements,choose the most appropriate answer from the options given below:

Which enzyme is required for the process shown in the figure below?

Which one of the following is called the resistance transfer factor?

Which microorganism is useful for $PCR$?