Question

1. why must viruses infect a host cell in order to reproduce? ★

a. host cells protect viruses from the immune system
b. viruses need energy stored in the host cell membrane
c. viruses use the host cell’s machinery to make viral components
d. viruses cannot survive outside of water

Explanation:

Viruses lack the cellular structures (like ribosomes, enzymes, and metabolic pathways) required to synthesize their own proteins, genetic material, and other components needed for reproduction. They rely entirely on hijacking the host cell's molecular machinery to replicate their genetic material and assemble new viral particles. Option A is incorrect because immune evasion is not the core reason for host dependency for reproduction. Option B is wrong as viruses do not use energy stored in the host cell membrane for reproduction. Option D is false because viruses can survive outside water (e.g., on surfaces) even if they are inactive.

Answer:

C. Viruses use the host cell's machinery to make viral components