Select the correct option regarding $Taq$ polymerase.

Refer to the following statements for agarose-gel electrophoresis :
$(a)$ Agarose is a natural polymer obtained from sea-weed.
$(b)$ The separation of $DNA$ molecules in agarose-gel electrophoresis depends on the size of $DNA$.
$(c)$ The $DNA$ migrates from negatively-charged electrode to the positively-charged electrode.
$(d)$ The $DNA$ migrates from positively-charged electrode to the negatively-charged electrode.
Choose the most appropriate answer from the options given below :

Which enzyme is used to release $DNA$ from a bacterial cell?

When foreign $DNA$ and a plasmid are cut by the same restriction endonuclease,which enzyme is used to join them to form a recombinant plasmid?

During 'gene cloning',which is called a gene taxi?

Which of the following is not a restriction endonuclease?