Match List-I with List-II.

	List-I		List-II
(A)	Kanamycin	(I)	Delivers genes into animal cells
(B)	Cla I	(II)	Selectable marker
(C)	Disarmed retroviruses	(III)	Restriction site
(D)	Kanamycin R gene	(IV)	Antibiotic resistance

Choose the correct answer from the options given below :

	(A)	(B)	(C)	(D)
(1)	II	III	I	IV
(2)	III	I	IV	II
(3)	IV	III	I	II
(4)	II	IV	I	III

A-II, B-III, C-I, D-IV

A. Kanamycin is a broad-spectrum antibiotic used as a selectable marker gene.

B. ClaI is a restriction site of 6 nucleotide length in pBR322. Restriction digestion of pBR322 with ClaI generates sticky ends. The enzyme is derived from a bacterium Caryophanon latum.

C. Retroviruses are a group of RNA viruses that infect animal cells and cause tumors. Disarmed retrovirus is a retrovirus from which the tumour causing genes are removed deliberately. It is used as a vector to deliver genes of interest into animal cells.

D. Kanamycin^R refers to kanamycin, which is an antibiotic resistant gene. It is used as a selectable marker gene. In molecular biology, a gene that helps in screening of bacterial or cell cultures for a desired trait is referred to as a selectable marker.