Tiny infectious agents that can only multiply when they are inside a host are called what?

Tiny infectious agents that can only multiply when they are inside a host are called what?

• A. Virus
• B. Bacteria
• C. Fungus
• D. Microorganism

Answer: (A)

Tiny infectious agents that can only multiply inside a host are viruses. They’re not cells and can’t carry out the life processes necessary for growth on their own. Instead, a virus must invade a living cell and hijack that cell’s machinery—its enzymes, ribosomes, and energy—to copy its genetic material and assemble new virus particles. That dependence on a host cell for replication is what sets viruses apart from cellular organisms like bacteria and fungi, which can grow and reproduce independently in suitable environments. The broad term microorganisms includes many different kinds, but only viruses fit the description of needing a host cell to multiply. For example, the influenza virus or HIV follows this pattern.

Tiny infectious agents that can only multiply inside a host are viruses. They’re not cells and can’t carry out the life processes necessary for growth on their own. Instead, a virus must invade a living cell and hijack that cell’s machinery—its enzymes, ribosomes, and energy—to copy its genetic material and assemble new virus particles. That dependence on a host cell for replication is what sets viruses apart from cellular organisms like bacteria and fungi, which can grow and reproduce independently in suitable environments. The broad term microorganisms includes many different kinds, but only viruses fit the description of needing a host cell to multiply. For example, the influenza virus or HIV follows this pattern.