Question

Arrange the following events of phage replication in correct sequence
A. Replication and synthesis
B. Penetration
C. Adsorption
D. Lysis and release
E. Assembly of phage particles
Choose the correct answer from the options given below

• A. B, E, C, A, D
• B. C, B, A, E, D
• C. C, B, A, E, D
• D. B, C, A, E, D

Hint:

Mnemonic: Attach \(\rightarrow\) Inject \(\rightarrow\) Make \(\rightarrow\) Assemble \(\rightarrow\) Burst.
The virus always lands (Adsorption) before it injects (Penetration).

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks for the chronological steps of the lytic cycle of a bacteriophage (a virus that infects bacteria). This process follows a very specific mechanical and biological order.

Step 2: Detailed Explanation:
The sequence of viral infection is as follows:

• Adsorption (C): The phage particles collide with the bacterial cell and attach to specific receptor sites on the cell wall using their tail fibers.

• Penetration (B): The phage injects its genetic material (DNA or RNA) into the host cell cytoplasm. The protein coat (capsid) remains outside as a "ghost."

• Replication and Synthesis (A): The host's metabolic machinery is hijacked. The phage genome directs the synthesis of viral proteins and the replication of viral nucleic acids.

• Assembly (E): The newly synthesized viral components (heads, tails, and DNA) are put together to form complete, mature phage particles. This is also called maturation.

• Lysis and Release (D): The bacterial cell wall is ruptured (often by the enzyme endolysin), and the new phages are released to infect neighboring cells.
Final Answer:
The sequence is C \(\rightarrow\) B \(\rightarrow\) A \(\rightarrow\) E \(\rightarrow\) D. This corresponds to option (B).