What are 'germs' anyway?

Help kids understand the definition of and difference between the four categories of germs.

In science class, students learn about single-cell organisms, fungi and many other living growing organisms. Generically, these organisms are called “germs” alternatively, microorganisms. There are four different categories of germs: bacteria, viruses, fungi and protozoa. To better understand each of these terms in the germ group let us define each one.

Bacteria are single cell organisms that can be both good and bad for our bodies. Bacteria can be found everywhere, even in the digestive tract. These germs can cause illness such as strep throat and infections. Having good hygiene and eating thoroughly cooked, and washed foods can help maintain a healthy amount of good bacteria in the body and ward off much of the bacteria that can cause illness.

This kind of germ cannot live on its own; viruses need a food source such as a living cell to survive. Viruses are tricky because they can live for a time on other surfaces until they find a new host – and they are always looking for a new home. Each virus can survive for a different length of time without a home. Some of them can live for an entire week on a surface if that surface is not disinfected.

Fungi is a multi-celled germ, a plant-like organism that can be seen without a microscope. Fungi grow on plants and animals in dark moist environments because that is where they get their source of nutrition. Fungi are not dangerous to healthy immune systems, but they can be very dangerous for someone that has a weakened immune system.

This is another single-celled organism that thrives on moisture. Contaminated water is often the source of protozoa. This germ can cause intestinal infections.

Germs can be found everywhere, so it is important to take precautions to help avoid getting sick. Michigan State University Extension encourages taking some simple steps like washing your hands properly, preserving foods correctly and cooking and storing foods safely.

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