Understanding Germs (Bacteria, Viruses and Fungi)

Author(s): Helen Hwang, Mary Mohrin, David Allyn, Mithril Cox

Lesson Overview

Grade level(s):

Elementary School (K-5), Grade 2, Grade 3, Grade 4


Biology/Life Science


Germs (bacteria, viruses and fungi), Personal Hygeine

Big ideas(s):

What are germs--how do they help and harm us?  What can we do to protect ourselves from "bad" germs?

Vocabulary words:

germs, bacteria, virus, fungi, vaccine

What you need:

Everything for this lesson was obtained from the SEP resource center: "Glow" lotion or powder with blacklight (K139) - can also be purchased here; Plush Toy Microbes (M197),  Germ Zappers by Balkwill and Mic Rolph (001003389), Posters (Bacteria: C246  Viruses: C238  Fungi: C250) as visuals/references ; agar plates for extension activity - request from SEP staff a week in advance


We start out with the entire class for story and class discussion to introduce germs.  We then break up into small groups of 2-4 for the "Name that Germ" activity.  Each group shares their germ with the rest of the class.  For the handwashing, you can send small groups out during the Name that Germ activity so there isn't a huge backup at the sink.  Visualizing with the blacklight will be done as a class.



Time needed:

approx 1 hour;  Introduction: Application of Glo Germ, free write, story and class discussion (15-20'); Name that Germ (15-20'); Handwashing and Blacklight (10');  Wrap-up (5')

Author Name(s): 
Helen Hwang, Mary Mohrin, David Allyn, Mithril Cox

This lesson focuses on understanding "germs" (specifically bacteria, viruses, and fungi), how they cause illness, how they can help us, and some lessons about personal hygiene (protecting ourselves from germs).  Students learn about the different classes of germs via a book and discussion, assign germ names, symptoms and modes of contraction to microbe stuffed animals, and finally try to wash "Glo Germ" off their hands to emphasize the importance of personal hygine.

Prerequisites for students: 

Previously we had covered cells and looked at them under a microscope or slide viewer, but this is not absolutely necessary.  It did however give the kids a better idea of how tiny germs can be.

Learning goals/objectives for students: 

Students will understand the different classes of germs - bacteria, viruses, and fungi -  and how they can both help and harm us.  At the end of the lesson they should be able to provide examples of each type of germ and the diseases they cause, and be aware of how easily they can be "passed on."  The kids should also understand the importance of cleanliness, washing their hands throroughly, covering their mouth when they sneeze or cough, etc.

Content background for instructor: 

See Weblink References for some basic background info and definition of terms.

Getting ready: 

Decide if you are going to do the agar plate extension.  If so, order the plates from the SEP resource center.  Otherwise, pour the agar plates yourself or order them from a scientific supply company (WARDS, Carolina Scientific). Get the materials ready to pass out and decide where you will plug in the black light.

Lesson Implementation / Outline


I 10'Have the kids rub the "Glow" lotion or powder on their hands but don't tell them what it's for--they will be intrigued! (At the end of the lesson we will tell them to wash their hands and look at everyone under the blacklight to see if they've done a good job.   Usually you will see lots of glowing hands-they get really excited!)  On the board, write: What are germs?  Have the kids write for a few minutes and then gather everyone together on the floor for a story/discussion about germs!


I 10' Storytime and Discussion:  This will be very casual, use the book Germ Zappers by Balkwill and Mic Rolph as a starting point (provides basic definitions) but the majority of this will be the students talking about real-life examples.

Start out with the simple question: What are germs?

Read short excerpts from the book Germ Zappers that describes:

-basic definition of germs

-the different classes of germs: (1) bacteria, (2) viruses, and (3) fungi

For each "class" of germs provide concrete examples.  For example, food poisoning can be caused by bacteria (a recent example the kids came up with was the spinach recall).  Bacteria can also help us with normal digestion, and are important part of food-making (yogurt).  For viruses you can talk about the common cold, the flu and chicken pox.  You can ask the kids how many have had these illnesses (everyone).  Here is a great place to talk about hygiene: sneezing, covering your mouth, washing your hands to prevent "passing on" germs.  While the book does not discuss fungi, you can mention this third class of germs, using athlete's foot and "ringworm" as examples.

II. 15-20' Name that Germ: pass out a GiantMicrobe stuffed animal to each group.  They are each labeled with a scientific or common name (i.e. Common cold).  (We taped these labels so the students didn't know the true identity of their microbe, but you can leave it).

We asked each group to provide the following information:

Name of the Microbe, Symptoms, How you catch it (mode of contraction), and how you can avoid catching it.

Note: It was really fun to hear the creative responses.  The stuffed animals have pretty distinctive characteristics that make them fun to work with and hint to how they would  be transmitted (form-function).  In fact, a lot of the kids created microbes that were very close to the real thing, and all this based on the cartoonish features.  After each group presents it is fun to reveal the true identity of the microbe and how it "really" acts.

III.  10' Handwashing/Blacklight:  During the "Name that Germ" activity begin sending the kids to the sink in small groups to wash their hands.  Once they are all back and washed, explain that the lotion/powder simulated "germs" and pass the blacklight over them.  It's funny to see how it gets on their desk and clothes and 99% of the time is all over their hands.  We teachers and volunteers also put the powder/lotion on and the kids "eew"-ed over how we had it all over us.

Wrap-up / Closure: 

To wrap-up, assemble the class once again on the carpet and ask them what they've learned from the day.  Especially after the blacklight and agar plate viewing they should have a lot to say!  Emphasize the importance of personal hygiene (handwashing etc.) and how these simple measures can protect us from "bad germs."

Extensions and Reflections

Extensions and connections: 

A week before the lesson, have the kids swipe their desk, the door knob, the sink, or anything in the classroom using their finger or a Q-tip.   Streak  these "samples" on agar plates (can be requested a week in advance from SEP) and let the bacteria and fungi multiply for a few days preferably in a dark warm place.  At the end of the lesson or as a follow-up lesson, examine the plates.  Ask students what these growths coudl be  Students will be able to see the colonies of bacteria and fungi (usuallly furry) on their plates.   Emphasize again the importance of washing your hands thorougly wtih soap and water and being careful about what you touch.


NGSS Topics
NGSS Disciplinary Core Ideas
NGSS Science and Engineering Practices
NGSS Crosscutting Concepts
NGSS Crosscutting Concepts: 

Standards - Grade 4

Life Sciences: 
3. Living organisms depend on one another and on their environment for survival. As a basis for understanding this concept:
d. Students know that most microorganisms do not cause disease and that many are beneficial.