Q.Match Column-I with Column-II and choose the correct option : Column-I a. Biolistic gun b. Chitinase c. Ti d. Ca++ Column-II i. Bacterial cell ii. Tumour inducing iii. Animal cell iv. Fungal cell v. Plant cell Options : a b c d (A) i ii iii iv (B) ii v i iii (C) v iv ii i (D) v i iv ii

Restriction enzymes are not directly relevant here; this question tests knowledge of gene transfer methods and their target organisms from biotechnology chapters.

The biolistic gun (gene gun) delivers DNA-coated metal particles into plant cells at high velocity, making it ideal for transforming crops like rice and wheat. Chitinase is an enzyme that degrades chitin, the main component of fungal cell walls, so it's used to breach fungal barriers during transformation or as a defense protein. The Ti plasmid (tumor-inducing plasmid) from Agrobacterium tumefaciens naturally infects plants and causes crown gall tumors, which is why it's called tumour inducing. Calcium ions (Ca²⁺) are used in the heat-shock method to make bacterial cells competent by creating transient pores in their membranes, allowing plasmid DNA to enter E. coli during transformation.

Matching them: …

The question draws from the molecular basis of genetic engineering and the methods used to introduce foreign DNA into different types of cells. Each tool or molecule in Column-I has a specific application or target, and understanding the underlying biology reveals the correct pairing.

a. Biolistic gun → v. Plant cell

The biolistic method, also called the gene gun technique, was developed specifically to overcome the challenge of introducing DNA into plant cells. Plant cells have rigid cell walls made of cellulose that resist many conventional transformation methods. The gene gun fires microscopic gold or tungsten particles coated with DNA at high velocity directly into plant tissues. The particles penetrate the cell wall and membrane, delivering the DNA into the nucleus. This physical method bypasses biological barriers and has been particularly successful with cereals and other monocots that are not natural hosts for Agrobacterium.

b. Chitinase → iv. Fungal cell

Chitin is a structural polysaccharide that forms the primary component of fungal cell walls (it also appears in the exoskeletons of arthropods). Chitinase is an enzyme that hydrolyses chitin, breaking down the β-1,4 linkages between N-acetylglucosamine units. In biotechnology, chitinase is used to digest fungal cell walls when researchers need to isolate fungal protoplasts—cells without walls—for genetic manipulation or fusion experiments. The enzyme essentially dissolves the protective outer layer, leaving the plasma membrane intact.

c. Ti → ii. Tumour inducing

Ti stands for tumour-inducing plasmid, a naturally occurring circular DNA molecule found in Agrobacterium tumefaciens. This soil bacterium infects plants at wound sites and transfers a segment of the Ti plasmid (the T-DNA) into the plant genome. The integrated T-DNA carries genes that force the plant cells to produce unusual amino acids (opines) and plant hormones, causing uncontrolled cell division—a crown gall tumour. Genetic engineers have disarmed the Ti plasmid by removing the tumour-causing genes while retaining the transfer machinery, turning it into a vector for introducing desirable genes into plants.

d. Ca²⁺ → i. Bacterial cell …