In genetic engineering,restriction enzymes are used to create:

The following diagram shows restriction sites in the $E. coli$ cloning vector $pBR322$. Identify the role of '$X$' and '$Y$' genes:

Given below are two statements :-
Statement-$I$ : Restriction endonucleases recognize specific sequences to cut $\text{DNA}$ known as selectable nucleotide sequences.
Statement-$II$ : Restriction endonucleases cut the $\text{DNA}$ 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 of the following statements is correct regarding the gel electrophoresis technique?

$BACs$ and $YACs$ are . . . . . . .

Which metals are used in a gene gun for the insertion of alien $DNA$ into a competent host?