Bacteriophages and animal viruses do not differ significantly in which one of the following steps of their replication cycles?

• A. Biosynthesis of viral nucleic acid and proteins
• B. Penetration into the host cell
• C. Attachment to host cell surface receptors
• D. Release from the host cell

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the replication cycle of both bacteriophages and animal viruses, which generally includes attachment, penetration, biosynthesis, maturation, and release.
2. Step 2: Analyze the attachment step, noting that both types of viruses must recognize and bind to specific receptors on the host cell surface, but the receptors and mechanisms can differ due to host cell type differences.
3. Step 3: Examine the penetration step, where bacteriophages often inject their nucleic acid into the bacterial cell, while animal viruses typically enter by endocytosis or membrane fusion, indicating differences in this step.
4. Step 4: Focus on the biosynthesis step, where viral nucleic acid and proteins are synthesized using the host's machinery; this process is fundamentally similar in both bacteriophages and animal viruses because it relies on the host cell's replication and translation systems.
5. Step 5: Consider the release step, which can differ as bacteriophages often cause cell lysis to release new virions, whereas animal viruses may bud off or cause lysis, showing variability in this step.