Question

Match List-I with List-II. List-I: A. T4, T1--T7, B. M13, fd, C. Lambda, D. Beta. List-II: I. Filamentous, II. Latent or lytic, III. Lytic, IV. Latent; codes for diphtheria toxin.

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

Hint:

Remember: T-even phages are lytic, M13/fd are filamentous, lambda phage can be lysogenic or lytic, and beta phage codes for diphtheria toxin.

Answer 1

The Correct Option is C

Concept:
Bacteriophages are viruses that infect bacteria. Different bacteriophages show different life cycles and structures. Some are strictly lytic, some are filamentous, and some may remain latent or enter the lytic cycle.

Step 1: Match T4, T1--T7.
T-even phages such as T4 are well-known lytic bacteriophages. They infect bacteria, multiply inside the host, and finally lyse the bacterial cell. \[ A \rightarrow III \]

Step 2: Match M13 and fd.
M13 and fd are filamentous bacteriophages. They are commonly used as cloning vectors and in phage display techniques. \[ B \rightarrow I \]

Step 3: Match Lambda phage.
Lambda phage can follow both lysogenic and lytic cycles. In the lysogenic state, it remains latent inside the bacterial genome, and under suitable conditions it enters the lytic cycle. \[ C \rightarrow II \]

Step 4: Match Beta phage.
Beta phage is associated with toxigenicity in Corynebacterium diphtheriae. It carries the gene responsible for diphtheria toxin production. \[ D \rightarrow IV \] Thus, the correct matching is: \[ A-III,\ B-I,\ C-II,\ D-IV \] \[ \therefore \text{Correct Answer is (C)} \]