Lesson Plan

Microorganisms: The Good, the Bad, and the Ugly

pools with green algae water

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Grade Level:
Middle School: Sixth Grade through Eighth Grade
Lesson Duration:
60 Minutes
State Standards:
Utah Core Curriculum
Sixth Grade Science

Standard 5: Objective 3


Activities explore the good that microorganisms do in food production, and the harm they can do in causing disease.


This guide contains background information about how microorganisms can be both good and bad, and directions for three activities that will help students better understand how microorganisms can be helpful and harmful. The activities are most beneficial to students when completed in order. This guide is specifically designed for sixth grade classrooms, but the activities can be modified for students at other levels. A separate activity guide, titled “What is a Microorganism?” provides a general introduction of microorganisms and their role in Zion National Park.


  • Download and review Microorganisms Activity Guide
  • Download and print activity materials
  • Gather lunches, picnic materials, and tape as necessary


Microorganisms: The Good, the Bad, and the Ugly Activity Guide

Download Microorganisms Activity Guide

The Good: Microorganisms in My Lunch Activity Materials

Download The Good

The Bad: Microorganisms and Disease Activity Materials

Download The Bad

The Ugly: Bighorn Sheep Mystery Activity Materials

Download The Ugly

Lesson Hook/Preview

Just as there are millions of different species of plants and animals in the world, there are millions of different species of microorganisms. Microorganisms can survive in environments where humans are unable to live. Microorganisms exist throughout the world, from Antarctica to your kitchen, from inside animals (like humans), to the expanse of wilderness in Zion National Park. Most are good, others are bad, and a few are just plain ugly.


Glossary available in activity guide.

Related Lessons or Education Materials

What is a Microorganism?

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Last updated: March 18, 2016