Question

Arrange the events that occurs in one life cycle of lytic bacteriophage in a order
A. Adsorption
B. Injection of Phage DNA
C. Releases of progeny phages
D. Production of phage components
E. Replication of the phage DNA
Choose the correct answer from the options given below:

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

Hint:

Bacteriophage infection always starts with adsorption and injection of genetic material, followed by intracellular replication and synthesis of structural proteins, and ends with host cell lysis.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The lytic cycle of a bacteriophage is the process by which a virus infects a bacterial cell, replicates its genome, synthesizes new viral structures, and lyses the host cell to release progeny.
This process follows a strict, highly regulated chronological order.
Detailed Explanation:
The lytic cycle proceeds through the following sequential stages:
1. Adsorption (A): The bacteriophage attaches to specific receptors on the surface of the bacterial host cell wall.
2. Injection of Phage DNA (B): The phage inserts its genomic DNA into the bacterial cytoplasm, leaving its protein capsid (sheath) outside.
3. Replication of Phage DNA (E): Once inside, the host's translation machinery is hijacked. The viral DNA is replicated to generate copies for new virions.
4. Production of Phage Components (D): Structural proteins (including head, tail, and fiber proteins) are transcribed and translated from the replicated viral DNA, followed by assembly into complete phage capsids.
5. Release of Progeny Phages (C): Phage-encoded enzymes (such as lysozyme) digest the bacterial cell wall, causing osmotic lysis of the host cell and releasing new mature virions.
Therefore, the correct chronological sequence is A $\rightarrow$ B $\rightarrow$ E $\rightarrow$ D $\rightarrow$ C.

Step 2: Final Answer:
The correct order is A, B, E, D, C, corresponding to Option (B).