Through this unit children learn that there are many very small organisms called micro-organisms which feed, grow and reproduce and which may be harmful or beneficial.
Work in this unit also offers children the opportunity to use scientific ideas to explain some causes of illness and decay, to relate micro-organisms to food production and to relate science to their personal health.
These are the smallest of the small and the simplest of the simple. Some of them, like viruses, may not even be alive as we currently define life.
What makes a microbe? We suppose you need a microscope to see them. That's about it. There is a huge variety of creatures in this section. They can work alone or in colonies. They can help you or hurt you.
Most important fact is that they make up the largest number of living organisms on the planet. It helps to be that small. It's not millions, billions, or trillions. There are trillions of trillions of trillions of microbes around the Earth. Maybe more. Microorganisms live almost everywhere on earth where there is liquid water, including hot springs on the ocean floor and deep inside rocks within the earth's crust.
The term microbe is short for microorganism, which means small organism. To help people understand the different types of microbes, they are grouped or classified in various ways. Here is an outline of the major groups of microorganisms: