Science Worksheet · Grades 3–5
Microorganisms Worksheet
A printable science worksheet for grades 3-5 on microorganisms – the tiny living things called bacteria, fungi, and protists. Students decide whether eight microbes are helpful or harmful, then answer four short questions about what microbes are and how to stay healthy. A complete answer key is included.
Subject
Science
Grades
Grades 3–5
Skill Focus
Microorganisms, life science
Lesson Length
20 minutes
Lesson Overview
About this worksheet
Microorganisms, or microbes, are living things too small to see without a microscope, such as bacteria, fungi, and protists. Some are helpful – yeast makes bread rise and gut microbes help digestion – while others are harmful germs that can make people sick. This worksheet helps students sort microbes into helpful and harmful.
Section A on page 1 lists eight microbes – yeast, mold, yogurt bacteria, cavity-causing bacteria, and more – and asks students to write helpful or harmful for each. The reference box teaches the idea with pond algae and airborne germs, which are not reused in any item.
Section B on page 2 asks what a microorganism is, names two kinds, asks for a helpful example, and explains why handwashing matters. Page 3 is a complete answer key with sample answers. The skill connects to germs, health, and ecosystems.
How to Use This Lesson
Read the reference box aloud and explain that microbes are everywhere, even inside us.
Complete Section A independently – have students ask ‘does this help people or hurt them?’
Discuss the surprising helpful microbes, like the fungus behind penicillin.
Use the answer key on page 3 for self-check.
Pair with the Human Body Systems Worksheet or the Decomposers Worksheet.
Printable Resource
A classroom-ready PDF with everything in one printable resource.
Full Member Resource · Printable PDF · 3 pages · Answer Key
Microorganisms Worksheet
A printable science worksheet for grades 3-5 on microorganisms – the tiny living things called bacteria, fungi, and protists. Students decide whether eight microbes are helpful or harmful, then answer four short questions about what microbes are and how to stay healthy. A complete answer key is included.
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