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What Do You Know About Microbes? (pre-assessment)

Author(s): Barbara Tharp, MS, and Nancy Moreno, PhD

Where are the microbes?

Now, turn students' attention toward their hands. The Glo Germ™ powder is barely visible under normal lighting conditions, but when students handled the liter bottles, some powder was transferred to their hands. With the small amount of magnification provided by a hand lens, the powder is slightly more visible. When students place their hands under a black light, the Glo Germ™ powder becomes fluorescent and easy to observe.

In this activity, the Glo Germ™ powder models microbes in the environment. Microbes are the most prevalent life forms on earth, both in mass and number. They are too tiny to be seen without magnification (in most cases, a microscope is required), yet microbes impact every human's entire life.

Students may think all microbes are harmful, but most are not. Explain that microbes produce most of the Earth's oxygen and are essential parts of all ecosystems. In addition, microorganisms are responsible for meeting many of the most vital human needs-such as aiding in digestion; protecting against other harmful microbes in the nose, skin and other body systems that might cause disease; and enabling the production of foods, such as sandwich bread and yogurt. Of course, some microbes are dangerous, cause illness, and are responsible for diseases that range from the common cold to malaria.

Funded by the following grant(s)

Science Education Partnership Award, NIH

Science Education Partnership Award, NIH

Grant Number: 5R25RR018605