Which one of the following is indispensable in genetic engineering?

In plants,the tumour inducing plasmid $(Ti)$ of $Agrobacterium$ $tumefaciens$ is used as a cloning vector. This statement is

The diagram below represents a schematic of recombinant $DNA$ technology. Which enzymes are responsible for the processes $P$ and $Q$ respectively?
$\quad\quad P\quad\quad\quad Q$

Identify true or false:
$(i)$ Restriction site is always a palindromic sequence.
$(ii)$ Palindromic sequence is always a restriction site.

Which one of the following hydrolyses internal phosphodiester bonds in a polynucleotide chain?

In $Ti$-plasmid, which of the following is removed: