What would be the fate of a lytic bacteriophage if its host cell died before the assembly stage?

• A. The bacteriophage would trigger the host cell to repair itself and resume assembly.
• B. The bacteriophage genome would integrate into the host chromosome as a prophage.
• C. The bacteriophage would immediately release mature virions into the environment.
• D. The bacteriophage would be unable to assemble new virions, halting the infection cycle.

Answer: (D)

Verified step by step guidance

1. Understand the lytic cycle of a bacteriophage, which involves the infection of a host bacterium, replication of the phage genome, synthesis of phage proteins, assembly of new virions, and finally lysis of the host cell to release new phages.
2. Recognize that the assembly stage is critical because it is when newly synthesized phage components come together to form complete, infectious virions.
3. Consider what happens if the host cell dies before the assembly stage: since the host cell machinery is required for assembling the phage particles, the death of the host cell would prevent this process from occurring.
4. Recall that in the lytic cycle, the phage genome does not integrate into the host chromosome (this is characteristic of the lysogenic cycle), so integration as a prophage would not happen here.
5. Conclude that without assembly, no mature virions can be formed or released, thus the infection cycle is halted and no new phages are produced.