In the process of transformation,$DNA$ is coated onto microparticles,which are bombarded using a gene gun. These microparticles are made of:

The chemical knives of $DNA$ are:

Hind $II$ always cuts $DNA$ molecules at a particular site called recognition sequence and it consists of : (in $bp$)

Which of the following is used in recombinant $DNA$ technology?

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 restriction site is present in the $tet^{R}$ gene in $pBR322$?