Which statement is NOT a characteristic of viruses?

Which statement is NOT a characteristic of viruses?

• A. They're obligate saprophytes
• B. They're obligate parasites
• C. They develop within the cell
• D. They're the smallest of all living organisms

Answer: (A)

The key idea is how viruses reproduce and what they rely on to do so. Viruses cannot survive or replicate on their own; they must invade a living cell and use that cell’s machinery. That makes them obligate parasites, and their development and assembly occur inside the host cell. The statement that they are obligate saprophytes is not correct because saprophytes obtain nutrients from decaying organic matter, using their own metabolic processes to digest and absorb it. Viruses lack metabolic activity and don’t "feed" on dead matter; they rely entirely on a host cell’s resources. The other statements fit what viruses do: they are obligate parasites (they require living hosts to reproduce) and they develop within the cell (replication and assembly happen inside the host cell). They’re extremely small, often described as the smallest infectious agents, which is why that characteristic is included.

The key idea is how viruses reproduce and what they rely on to do so. Viruses cannot survive or replicate on their own; they must invade a living cell and use that cell’s machinery. That makes them obligate parasites, and their development and assembly occur inside the host cell.

The statement that they are obligate saprophytes is not correct because saprophytes obtain nutrients from decaying organic matter, using their own metabolic processes to digest and absorb it. Viruses lack metabolic activity and don’t "feed" on dead matter; they rely entirely on a host cell’s resources.

The other statements fit what viruses do: they are obligate parasites (they require living hosts to reproduce) and they develop within the cell (replication and assembly happen inside the host cell). They’re extremely small, often described as the smallest infectious agents, which is why that characteristic is included.