Cells are the smallest structures capable of basic life processes, such as taking in nutrients, expelling waste, and reproducing. All living things are composed of cells. Some microscopic organisms, such as bacteria and protozoa, are unicellular, meaning they consist of a single cell. Plants, animals, and fungi are multicellular, meaning they are composed of a great many cells working all together. But whether it makes up an entire bacterium or is just one of trillions in a human being, the cell is a miracle of design and efficiency. …
