Which statement describes viruses?

• A. Living and replicate independently
• B. Nonliving and replicate in cells of other organisms
• C. Have a nucleus enclosed by a membrane
• D. Do not contain genetic material

Answer: (B)

Viruses are nonliving particles outside a host because they cannot carry out metabolism or reproduce on their own. They are made of genetic material (DNA or RNA) wrapped in a protein coat, and sometimes a lipid envelope, but they lack the cellular machinery needed to grow or generate energy. To replicate, they hijack a living cell’s machinery, turning the cell into a factory to produce new virus particles. They also don’t have a nucleus or any membrane-bound organelles, since they are not cells. The key idea is that viruses rely on infecting cells to reproduce, which is why the description of them as nonliving and needing a host for replication is correct. They do contain genetic material, so saying they lack genetic material isn’t accurate, and they don’t replicate independently without a host.