What microscopic structure contains genetic material and can multiply only inside living host cells?

What microscopic structure contains genetic material and can multiply only inside living host cells?

• A. Bacterium
• B. Prion
• C. Virus
• D. Fungus

Answer: (C)

Viruses are genetic-material–containing particles that cannot reproduce on their own and must hijack living host cells to multiply. They carry either DNA or RNA and rely on the host’s enzymes, ribosomes, and metabolic machinery to replicate and assemble new viral particles. This obligate intracellular nature is what sets viruses apart from other microscopic structures. Bacteria are single-celled organisms with their own metabolism and replication machinery, so they don’t need a host cell to reproduce. Prions have no genetic material at all, so they don’t encode information to replicate like viruses do. Fungi are cellular organisms with nuclei and metabolisms of their own, capable of growth and reproduction without a host.

Viruses are genetic-material–containing particles that cannot reproduce on their own and must hijack living host cells to multiply. They carry either DNA or RNA and rely on the host’s enzymes, ribosomes, and metabolic machinery to replicate and assemble new viral particles. This obligate intracellular nature is what sets viruses apart from other microscopic structures.

Bacteria are single-celled organisms with their own metabolism and replication machinery, so they don’t need a host cell to reproduce. Prions have no genetic material at all, so they don’t encode information to replicate like viruses do. Fungi are cellular organisms with nuclei and metabolisms of their own, capable of growth and reproduction without a host.