Bacteria Growth Inquiry: Bodily Bacteria and Healthy Hygiene Habits
Summary
In this inquiry activity, groups of students will generate investigable questions to explore the link between hygiene/cleanliness and bacteria growth/population. They will record their processes and reflections in a journal and present their findings to their classmates. The class will discuss the conclusions found in the investigations, and the teacher will present additional information using internet film clips.
CollapseLearning Goals
Students will work cooperatively to generate an investigable question relating to hygiene and bacteria found on the human body, create a plan to investigate their question using the materials provided, conduct their investigation, and record their observations/data in their discovery journals. Through this inquiry, students will discover that bacteria is found on all parts of the body and can reproduce. Students will also determine that regular cleansing results in fewer bacteria. The students will recognize that most bacteria is harmless, but some can make them ill. They will also discuss why antibacterial soaps and cleaners may not be the best choice on a daily basis.
Vocabulary:
-Bacteria
-Hygiene
-Antibacterial
-Antiseptic
-Antibiotic
-Colony
-Culture
-Organism
-Incubate
-Agar
-Petri dish.
Vocabulary:
-Bacteria
-Hygiene
-Antibacterial
-Antiseptic
-Antibiotic
-Colony
-Culture
-Organism
-Incubate
-Agar
-Petri dish.
Context for Use
This is an integrated science activity geared for my 4th grade health class to help them understand the importance of hygiene and cleanliness. This lesson will lead into a unit about the body's defenses against disease. The lesson will take several days to complete in order to allow the bacteria time to reproduce. Students must be comfortable formulating and documenting the components of their investigations in their journals.
Description and Teaching Materials
Materials Needed For All Students:
-Petri dishes filled with prepared agar (minimum of 2 per group)
-Masking tape and permanent markers (for labeling petri dishes)
-Clear packing tape
-Journals
-Writing utensils
Possible Items Students May Use For Inquiry:
-Bar of soap
-Liquid soap (regular and antibacterial)
-Foam soap (regular and antibacterial)
-Hand sanitizer
-Cotton swabs
-String
-Toothpicks
-Dental floss
-Toothbrushes (new)
-Toothpaste
-Mouthwash (regular and antiseptic)
-Fingernail cleaner
-Disinfectant wipes
-Microscope and slides
*DO NOT remove the packing tape after sealing the petri dishes. The bacteria inside can pose a health risk. Seal the petri dishes in a plastic bag before disposing of them.
Several days before conducting this inquiry, have the students observe as you swab a sink or computer keyboard for bacteria to incubate and use as example. Explain each step of the sampling process, but don't tell them what you are looking for. Hold up the petri dish and ask the students to observe what's inside.
Allow the culture to incubate for several days until a bacteria colony is observable.
Walk the petri dish around the classroom and ask the students to again observe what is inside. Have the students generate questions and record them on a large piece of paper. (examples: What is it? How did it get there? Why couldn't we see it before? Did it come from the sink? Is it alive? etc...) Put these questions aside to be answered later. Then, pose your own question for the students: Do you think that this stuff is on us too?
Tell the students that they are going to think of their own investigable question and conduct an investigation in groups. They may use any of the materials provided on the table.
Demonstrate again for the students how to sample an area using a cotton swab, a piece of string/floss (enclose in petri dish), and/or a toothpick (enclose in petri dish). Discuss the importance of avoiding cross contamination by handling the tools, touching other things, etc...
Students may create their own inquiry questions independently, or you may generate questions as a class to get them started.
Divide students into small learning groups (2-4 students). Each group must determine a question that they want to investigate. Conference briefly with each group once they have established their plan: What do you want to know? What is your plan/procedure? What are you measuring? How does your test show what you want to know? What do you predict will happen?
When the students' plan has been approved, they may proceed with their inquiry.
BE CERTAIN THAT YOU SEAL THE TOP AND BOTTOM OF EACH PETRI DISH SECURELY WITH THE PACKING TAPE BEFORE ALLOWING THE BACTERIA TO INCUBATE!!! Inform students that the dishes MUST REMAIN SEALED for the remainder of the experiment, and store them in an area where students do not have access.
Several days later, when bacteria cultures are evident, have the students reexamine the petri dishes, analyze their data, and draw their conclusions. The groups should present their work to the class. Discuss as a group.
Show the students the following educational movie clips about bacteria and guide discussion after each:
61 second clip showing that bacteria is found all over the human body:
http://videos.howstuffworks.com/hsw/10405-bacteria-bacteria-are-everywhere-video.htm
1 min. 46 sec. clip of animated singing rats explain why the bacteria colonies grew enough to be visible in the petri dish:
http://www.teachertube.com/view_video.php?viewkey=f15d63acdfa2df2f088e
2 min. clip explaining how bacteria can make people ill:
http://videos.howstuffworks.com/hsw/12705-the-bodys-defense-against-disease-the-enemy-within-video.htm
1 min. 34 sec. clip about Antibiotics and bacteria:
http://videos.howstuffworks.com/hsw/6076-disease-defense-antibiotics-video.htm
3 min. CBS News clip comparing antibacterial to regular soap:
http://www.cbsnews.com/video/watch/?id=961404n%3fsource=search_video
Reexamine the question list the class generated earlier. See if the students are now able to provide answers.
Discussion/Response Questions: Give examples of personal hygiene. Why is personal hygiene important? Is bacteria bad for you? Explain. What is an antibiotic? What do antibacterial and antiseptic products do? Should we use them every day? Why/why not?
Extension: ask the students to brainstorm a list of things that people wash. Categorize that list to identify things that should be washed daily and multiple times throughout the day. Ask the students to consider reasons for this.
Extension: research ways bacteria are beneficial to humans and the environment.
-Petri dishes filled with prepared agar (minimum of 2 per group)
-Masking tape and permanent markers (for labeling petri dishes)
-Clear packing tape
-Journals
-Writing utensils
Possible Items Students May Use For Inquiry:
-Bar of soap
-Liquid soap (regular and antibacterial)
-Foam soap (regular and antibacterial)
-Hand sanitizer
-Cotton swabs
-String
-Toothpicks
-Dental floss
-Toothbrushes (new)
-Toothpaste
-Mouthwash (regular and antiseptic)
-Fingernail cleaner
-Disinfectant wipes
-Microscope and slides
*DO NOT remove the packing tape after sealing the petri dishes. The bacteria inside can pose a health risk. Seal the petri dishes in a plastic bag before disposing of them.
Several days before conducting this inquiry, have the students observe as you swab a sink or computer keyboard for bacteria to incubate and use as example. Explain each step of the sampling process, but don't tell them what you are looking for. Hold up the petri dish and ask the students to observe what's inside.
Allow the culture to incubate for several days until a bacteria colony is observable.
Walk the petri dish around the classroom and ask the students to again observe what is inside. Have the students generate questions and record them on a large piece of paper. (examples: What is it? How did it get there? Why couldn't we see it before? Did it come from the sink? Is it alive? etc...) Put these questions aside to be answered later. Then, pose your own question for the students: Do you think that this stuff is on us too?
Tell the students that they are going to think of their own investigable question and conduct an investigation in groups. They may use any of the materials provided on the table.
Demonstrate again for the students how to sample an area using a cotton swab, a piece of string/floss (enclose in petri dish), and/or a toothpick (enclose in petri dish). Discuss the importance of avoiding cross contamination by handling the tools, touching other things, etc...
Students may create their own inquiry questions independently, or you may generate questions as a class to get them started.
Divide students into small learning groups (2-4 students). Each group must determine a question that they want to investigate. Conference briefly with each group once they have established their plan: What do you want to know? What is your plan/procedure? What are you measuring? How does your test show what you want to know? What do you predict will happen?
When the students' plan has been approved, they may proceed with their inquiry.
BE CERTAIN THAT YOU SEAL THE TOP AND BOTTOM OF EACH PETRI DISH SECURELY WITH THE PACKING TAPE BEFORE ALLOWING THE BACTERIA TO INCUBATE!!! Inform students that the dishes MUST REMAIN SEALED for the remainder of the experiment, and store them in an area where students do not have access.
Several days later, when bacteria cultures are evident, have the students reexamine the petri dishes, analyze their data, and draw their conclusions. The groups should present their work to the class. Discuss as a group.
Show the students the following educational movie clips about bacteria and guide discussion after each:
61 second clip showing that bacteria is found all over the human body:
http://videos.howstuffworks.com/hsw/10405-bacteria-bacteria-are-everywhere-video.htm
1 min. 46 sec. clip of animated singing rats explain why the bacteria colonies grew enough to be visible in the petri dish:
http://www.teachertube.com/view_video.php?viewkey=f15d63acdfa2df2f088e
2 min. clip explaining how bacteria can make people ill:
http://videos.howstuffworks.com/hsw/12705-the-bodys-defense-against-disease-the-enemy-within-video.htm
1 min. 34 sec. clip about Antibiotics and bacteria:
http://videos.howstuffworks.com/hsw/6076-disease-defense-antibiotics-video.htm
3 min. CBS News clip comparing antibacterial to regular soap:
http://www.cbsnews.com/video/watch/?id=961404n%3fsource=search_video
Reexamine the question list the class generated earlier. See if the students are now able to provide answers.
Discussion/Response Questions: Give examples of personal hygiene. Why is personal hygiene important? Is bacteria bad for you? Explain. What is an antibiotic? What do antibacterial and antiseptic products do? Should we use them every day? Why/why not?
Extension: ask the students to brainstorm a list of things that people wash. Categorize that list to identify things that should be washed daily and multiple times throughout the day. Ask the students to consider reasons for this.
Extension: research ways bacteria are beneficial to humans and the environment.
Teaching Notes and Tips
Safety Guidelines: DO NOT allow students to remove the packing tape after sealing and incubating the petri dishes. Bacteria colonies can pose a health risk to students if they are exposed. Seal the petri dishes in a plastic bag before disposing of them.
Students must be familiar with formulating and documenting the components of an investigation in their journals. They must be capable of independently completing an inquiry experiment with oversight and occasional guidance from the teacher.
This lesson's discovery-based approach and student-posed investigation questions make it unique from the typical bacteria sampling activity where students are supplied most of the answers and expected outcomes prior to experimentation.
Students must be familiar with formulating and documenting the components of an investigation in their journals. They must be capable of independently completing an inquiry experiment with oversight and occasional guidance from the teacher.
This lesson's discovery-based approach and student-posed investigation questions make it unique from the typical bacteria sampling activity where students are supplied most of the answers and expected outcomes prior to experimentation.
Assessment
In addition to informal observation throughout the inquiry process, discussions, and student presentations, teachers should assess student understanding by viewing their written work in their journals.
Standards
Grade 4
Strand I. History and Nature of Science,
Sub-Strand A. Scientific World View, Standard: The student will understand how science is used to investigate interactions between people and the natural world.
Benchmark 1: The student will explore the uses and effects of science in our interaction with the natural world.
Benchmark 2: The student will discuss the responsible use of science.
Benchmark 3: The student will recognize the impact of scientific and technological activities on the natural world.
Sub-Strand B. Scientific Inquiry, Standard: The student will participate in a controlled scientific investigation.
Benchmark 2: The student will collect, organize, analyze, and present data from a controlled experiment.,
Benchmark 3: The student will recognize that evidence and logic are necessary to support scientific understandings.
Strand IV. Life Science
Sub-Strand G. Human Organism, Standard: The student will know the structures that serve various functions in the human body, including protection from disease.
Benchmark 2: The student will know that germs entering the body can cause disease, and that the body has defenses against these germs.
Strand I. History and Nature of Science,
Sub-Strand A. Scientific World View, Standard: The student will understand how science is used to investigate interactions between people and the natural world.
Benchmark 1: The student will explore the uses and effects of science in our interaction with the natural world.
Benchmark 2: The student will discuss the responsible use of science.
Benchmark 3: The student will recognize the impact of scientific and technological activities on the natural world.
Sub-Strand B. Scientific Inquiry, Standard: The student will participate in a controlled scientific investigation.
Benchmark 2: The student will collect, organize, analyze, and present data from a controlled experiment.,
Benchmark 3: The student will recognize that evidence and logic are necessary to support scientific understandings.
Strand IV. Life Science
Sub-Strand G. Human Organism, Standard: The student will know the structures that serve various functions in the human body, including protection from disease.
Benchmark 2: The student will know that germs entering the body can cause disease, and that the body has defenses against these germs.