What Is A Virus?
Biologists have divided, or classified, living things into five kingdoms. These kingdoms are Monera, Protista, Fungi, Plants, and Animals. Each of these kingdoms is made up of lifeforms which are similar to one another in important ways.
One thing that all five kingdoms have in common is that they are all made up of cells. Every plant, fungus, animal, moneran, and protist is made up of at least one cell, and in some cases, millions or even billions of cells. For this reason, biologists say that the basic unit of life is the cell. In other words, the cell is the smallest unit that makes up a living thing.
Have you ever heard the word “virus?” What is a virus? Some common viruses you are probably familiar with (and may have even been infected by) are chicken pox, the common cold, measles, and mumps. A virus does not belong to any of the five kingdoms of life. Even more odd, a virus is not made up of cells. Viruses do not eat, they do not produce waste, nor do they do many of the functions that other living things do. In fact, the only thing they can do is reproduce.