What modification is done on the $Ti$ plasmid of Agrobacterium tumefaciens to convert it into a cloning vector?

What is the function of a selectable marker?

Which of the following enzyme$(s)$ are $\text{NOT}$ essential for gene cloning?
$A.$ Restriction enzymes
$B.$ $\text{DNA}$ ligase
$C.$ $\text{DNA}$ mutase
$D.$ $\text{DNA}$ recombinase
$E.$ $\text{DNA}$ polymerase
Choose the correct answer from the options given below:

$A$ : $DNA$ ligase plays an important role in recombinant $DNA$ technology.
$R$ : The linking of antibiotic resistance gene with plasmid vector became possible by enzyme $DNA$ ligase.

The plasmid used for the construction of the first artificial recombinant $DNA$ molecule was obtained from which microorganism?

Match the following enzymes with their functions:

$(a)$ Restriction endonuclease	$(i)$ Joins the $DNA$ fragments
$(b)$ Restriction exonuclease	$(ii)$ Extends primers on genomic $DNA$ template
$(c)$ $DNA$ ligase	$(iii)$ Cuts $DNA$ at specific positions
$(d)$ $Taq$ polymerase	$(iv)$ Removes nucleotides from the ends of $DNA$

Select the correct option from the following: