The $Ti$ plasmid is frequently used in plant transformation. This plasmid is found in .......

Which microorganism is useful for $PCR$?

The enzyme used during $\text{PCR}$ is$-$
$I.$ Taq polymerase
$II.$ Helicase
$III.$ $\text{RNA}$ polymerase
$IV.$ Gyrase
Select the correct option:

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 has popularized the $PCR$ (polymerase chain reaction)?

$A$ simple segment of a $DNA$ strand is shown,which provides the base sequence for its complementary strand. What is specifically indicated here?