Question

Arrange the following events of lytic cycle of virus in a sequence: A) Phage DNA is assembled in the protein to form viral particles. B) Bacterial cell lysis, releasing completed infective phages. C) The phage DNA directs the cell's metabolism to produce viral components. D) Phage attaches to receptor site of bacterial cell.

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

Hint:

Attach $\rightarrow$ Synthesize $\rightarrow$ Assemble $\rightarrow$ Lyse (Release).

Answer 1

The Correct Option is A

Step 1: Recall the lytic cycle.
The lytic cycle of a bacteriophage runs in a fixed order: the phage attaches, takes over the cell, builds new parts, assembles them, and finally bursts the cell. We just need to order the four events.

Step 2: Find the first event.
Nothing can happen until the phage lands on the cell. Event D, the phage attaches to the receptor site, must be first.

Step 3: Find the next event.
After attaching, the phage DNA enters and takes control. Event C, where phage DNA directs the cell to make viral components, comes second.

Step 4: Find the third event.
Once the parts are made, they are put together. Event A, where DNA is packed into protein coats to form particles, comes third.

Step 5: Find the last event.
Finally the cell breaks open to set the new phages free. Event B, cell lysis and release, comes last.

Step 6: Write the sequence.
The order is D, C, A, B, which is the first option.
\[ \boxed{\text{D, C, A, B}} \]