The host range of a virus is determined by which of the following factors?

• A. The presence of a cell wall in the host organism
• B. The metabolic rate of the host cell
• C. The specific attachment molecules on the viral surface and the corresponding receptors on the host cell
• D. The size of the viral genome

Answer: (C)

Verified step by step guidance

1. Understand that the host range of a virus refers to the spectrum of host cells or organisms that a virus can infect.
2. Recognize that the key factor determining host range is the ability of the virus to attach to the host cell, which depends on specific interactions between viral surface molecules and host cell receptors.
3. Note that the presence of a cell wall or the metabolic rate of the host cell does not directly determine whether a virus can infect that cell, although they may influence other aspects of infection.
4. Acknowledge that the size of the viral genome is unrelated to the host range; it affects viral replication and complexity but not which hosts can be infected.
5. Conclude that the specific attachment molecules on the viral surface and the corresponding receptors on the host cell are the primary determinants of the virus's host range.