Which term describes an organism that is too small to be seen with the naked eye?

• A. Organisms
• B. Cells
• C. Microorganism
• D. Bacteria

Answer: (C)

The main idea is size and the definition of living things. A microorganism is a living thing so small that you need a microscope to see it. That makes it the best fit for describing an organism that’s too tiny to be seen with the naked eye. Organisms is a broad term for all living things, some of which are visible, so it’s too general. Cells are the basic units of life, not necessarily whole living beings, and some organisms are made of many cells. Bacteria is a specific group of microorganisms, so while bacteria are tiny, the term micro­organism covers the widest range of microscopic living things.