In addition to $Taq$ polymerase enzyme,which other thermostable $DNA$ polymerases have been isolated to be used in Polymerase Chain Reaction $(PCR)$?

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 $I$: Plasmids are autonomously replicating $DNA$.
Statement $II$: Plasmids are extrachromosomal $DNA$.
In the light of the above statements, choose the correct answer from the options given below:

Which one of the following is commonly used in the transfer of foreign $DNA$ into crop plants?

$A$ plasmid without a selectable marker was chosen as a vector for cloning a gene. How does this affect the experiment?

Which of the following has popularized the $PCR$ (polymerase chain reaction)?