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

• A. Cells
• B. Sun
• C. Microorganism
• D. Terminator

Answer: (C)

The idea being tested is how size relates to what we call living things. An organism that is too small to be seen without a microscope is described as a microorganism. The prefix micro- means small, and organism means a living thing, so together they specify living beings that require magnification to be seen. Examples include bacteria, yeasts, protozoa, and many microscopic fungi (and sometimes viruses, depending on the definition used). A cell is the basic unit of life, but the term doesn’t specify size or living status on its own—some cells are microscopic, but the word refers to a unit of life rather than to the overall size category of the organism. The Sun is a star, not an organism, and Terminator is a fictional character, so they don’t fit. That makes microorganism the best descriptor for something too small to see with the naked eye.