Which enzyme is used to synthesize a $cDNA$ probe from a messenger $RNA$ molecule?

Which of the following is not correctly matched for the organism and its cell wall degrading enzyme?

Why is a vector necessary for obtaining the desired product in recombinant $DNA$ technology?

The enzyme known as restriction endonuclease:

Which of the following is the first restriction endonuclease discovered?

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 :