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The Variety and Roles of Microbes

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

Examples of Microbes as Causes of Disease

The majority of microbes are not harmful, and many are helpful. But some microbes, called pathogens*, infect and cause disease in host organisms, which may be humans, plants, animals or even other microbes. Many species have immune system responses designed to slow or stop the growth of different microbes. In addition, in cases of diseases in humans or domesticated plants and animals, it is possible to use additional antimicrobial agents.

Ask students to identify differences and similarities between microbes used in food production and those that cause disease. Lead a discussion about the different roles of microbes, making sure that students understand that different types of microbes have overlapping roles (e.g., both bacteria and fungi carry out fermentation). Ask students to make general statements about the roles of microbes and the various microbe groups (e.g., “Some microbes are helpful, but others can be dangerous.”).

Finally, ask students to explain why we should care about microbes, and have them record any new ideas on their concept maps.

*A pathogen is any disease-causing organism.

Funded by the following grant(s)

Science Education Partnership Award, NIH

Science Education Partnership Award, NIH

Grant Number: 5R25RR018605