There’s a Small World Out there Part 3: Coming Soon to a Person Near You
PURPOSE: To explore the transmission of disease and better understand the reproduction potential of bacteria.
GOAL/OBJECTIVE
Goal 1 –The learner will design and conduct investigations to demonstrate an understanding of scientific inquiry.
Objectives 1.01, 1.05, 1.08, 1.09, 1.10
Goal 7 – The learner will conduct investigations, use models, simulations, and appropriate technologies and information systems to build an understanding of cell theory.
Objective 7.03, 7.04
Language (ELD) Objective: The learner will - M
ENGAGE:
As the students enter the classroom, have the title of this part written on the board – “Coming Soon to a Person Near You.” Just before the students enter the classroom, pour ammonia into a small beaker and swirl it as students enter the room. Do not let the students know what liquid is being used. This liquid has a distinct odor. As soon as the students are all seated, instruct them to stand as they smell the odor and observe the order in which the students begin to stand. The student closest to the ammonia should stand first as the smell penetrates the room. Lead the students into a discussion about how the smell traveled
throughout the room (time, pattern of movement, strength of odor, etc.) and compare the spread of the smell to the spread of germs. Ask the following questions:
1. How quickly did you detect the odor?
2. How did this compare to other students in the classroom?
3. Was there a pattern of movement as the smell traveled around the room? 4. Could some students smell the odor better than others?
5. Could you see the smell as it traveled to your nose? 6. How does this activity model the spread of germs? 7. Can you see germs that are around you?
Alternate or Additional Activity: Use Glow Germ (can be purchased through catalog) on the door knob or other object that students would come in contact with when they enter the classroom. After everyone is seated, tell the students that some of them have been infected with a “germ.” Use a black light to see who has been infected and discuss how they might have become infected. Ask the following questions: (See transparency, page 40.)
1. How many of you have been infected with the germ? 2. How do you think you came in contact with the germ?
3. Why have some people been infected with the germ and others have not? 4. How can we find out where the germ is located in the classroom?
5. How does this activity show how germs are spread in real life?
6. Can you see the germs you come in contact with in real life like we did with the black light?
7. How do scientists determine if you have an infectious germ?
EXPLORE:
Have a class discussion about how diseases are transmitted from one person to another. Use the following questions to guide your discussion:
1. How many of you have had a cold or stomach “bug?” Did anyone else in your family get sick at the same time?
2. What do you think caused you to get sick? Can you see the things that caused you to get sick?
3. How are sickness and disease transmitted from one person to another? 4. How does the sickness get inside your body? (Inhalation, ingestion, and
absorption)
5. What are some things that you can do to help stop the spread of sickness and disease?
Use the following activity to simulate the transmission of a virus. See page 42 for handout, “Simulation: The Spread of Disease.”
Preparation before class arrives:
1. You will need 2 small cups or clear film canisters for each person in class. Number the pairs of cups consecutively. Each cup will contain simulated “body fluid.”
2. Prepare a tray with two cups for each person in the group, a small beaker of “virus detection solution” (phenolphthalein indicator), pipettes or
droppers, and safety equipment.
3. Prepare the “virus” by mixing baking soda in water to form a clear solution. Stir until all the baking soda is dissolved. Place the “virus” in only one student’s pair of cups. Record the number of the pair of cups that
contains the “virus” (baking soda). Keep this a secret. Pour water in the remaining cups.
4. Make a transparency of the data table to record the class data.
* Use the activity sheet for students to complete as they do this activity.
After the students have completed the exchange of body fluids, ask the students to make a foldable or other vocabulary development activity (such as the Frayer Model - Frayer, D., Frederick, W. C., and Klausmeier, H. J. (1969). A
Schema for Testing the Level of Cognitive Mastery. Madison, WI: Wisconsin Center for
Education Research.) for key vocabulary terms related to the transmission of disease. Discuss these vocabulary words in class: vector, carrier,
pathogen, contagion, mutagen. These words have been defined on page 48-49.
Discuss conditions conducive to the spread of disease. You can use this website for more information or have your students play the infection game.
http://www.amnh.org/nationalcenter/infection/03_inf/03_inf.html
Ask the students to research various diseases and how they are spread to others. (A list is included for you to assign diseases.) Have the students present their findings to the class in a brochure, multimedia presentation, or newsletter. There is transparency attached for the students to pick a
disease or the teacher can assign the diseases. There is also a handout attached for the students to use for recording information during the presentations in class.
ELABORATE:
For the ELABORATE, you will need to go step by step with the students through the process. Discuss how bacteria reproduce using binary fission (the process where the organism divides into two identical offspring with each having an exact copy of the parent genetic material.) Draw a diagram on the board to show the reproductive potential of a bacterium in one hour.
1 hour
Ask students the following questions:
1. According to this diagram, how long does it take for this bacterium to divide? (every 20 minutes)
2. What is the reproductive potential of this bacterium under ideal conditions in 24 hours? Give the students time to work this out in groups. (They can continue drawing the diagram to look for the pattern and figure out the formula (272). Or, they can multiply it out. The students will get to a point and figure out that it is a BIG number.)
Next, ask the students to create a web showing the people they have come in contact with in the last 24 hours. They should place themselves in the middle of the web and each person contacted will be placed on the outside of the web.
Ask how many contacts each student has made and calculate a class average for number of contacts. The spread of bacteria from one person to another is also an example of exponential growth. Ask the students to think about the 24-hour growth potential they calculated for one bacterium. Suppose those bacteria have spread to all their contacts. If the bacteria continue to reproduce and
spread to all contacts at the same rate, what impact could these bacteria have on the town you live in if they were deadly bacteria? Is this likely to happen? Why or why not?
EVALUATE:
The students can do one or more of the following:
1. Using a publisher program, make a flyer to be displayed in the school to show techniques that can be used to help prevent the spread of disease, such as hand washing, not sharing drinking cups, keeping work surfaces clean, correct food preparation, etc. Assess the poster using a rubric. 2. Prepare a presentation to teach young students about the importance of
washing their hands. Make arrangements with a 1st-grade teacher to present the presentation to their students.
3. Complete the compare and contrast graphic organizer on vaccines and antibiotics.
4. Questions to write about:
a. Why is it important for medical researchers to understand how a virus is spread from person to person?
b. Why is it important for you to understand how a virus is spread from person to person?
c. What are some ways that people can help prevent the spread of viruses?
5. Make a 3-tab foldable for three diseases, strep throat, AIDS, and malaria.
Front of foldable:
Me
Inside of foldable (for each disease):
Caused by: Caused by: Caused by:
Treatment: Treatment: Treatment:
Statistics: Statistics: Statistics:
Additional Resources
http://www.amnh.org/exhibitions/epidemic/index.html
“Epidemic: The World of Infectious Disease” – This site contains a wealth of information on microbes and the disease they cause. It is an excellent resource for teachers and students.
http://www3.niaid.nih.gov/research/topics
This site provides information about the National Institute of Allergy and Infectious Diseases basic and clinical research on allergy, immunology, and infectious diseases. It includes information about the diseases studied, the research findings, and press releases.
West Nile Virus
http://www.westnilefever.com/index.html
World Health Organization – Smallpox http://www.who.int/csr/disease/smallpox/en/
Hidden Worlds Collide
http://www.sciencenews.org/sn_arc97/2_8_97/bob1.htm
Emerging Infectious Diseases
http://www.cdc.gov/ncidod/diseases/eid/index.htm
Anthrax
Special Pathogens Branch
ENGAGE, Part 3
Germs All Around You
1. How many of you have been infected with
the germ?
2. How do you think you came in contact with
the germ?
3. Why have some people been infected with
the germ and others have not?
4. How can we find out where the germ is
located in the classroom?
5. How does this activity show how germs are
spread in real life?
6. Can you see the germs you come in contact
with in real life like we did with the black
light?
EXPLORE, Part 3 Name ___________________________________
Handout Date
____________________________________
Simulation: The Spread of Disease
In this lab activity, you will simulate the spread of an undiagnosed virus through your class. At first, only one person in the class will be infected with the virus. That person, the “index case,” will be unaware that he or she is infected, which is often the case in reality. You will be given a cup containing a clear fluid that will represent your body fluid. You will exchange your body fluid with three other people in the class. At the end of the activity, you will test your simulated fluid for the presence of the virus and identify the original infected person, “patient zero.”
Note: You will not be working with a real virus. This is only a simulation. Caution: The virus detection solution is flammable. Do not use it near open flames. Avoid any contact with the skin or eyes.
Materials for each group:
2 numbered cups of “body fluid” for each person in the group
Virus detection solution Pipette or dropper Goggles
Procedure:
1. Wear your safety goggles while completing the lab.
2. Each person in your group will select a pair of numbered cups containing “body fluid” and record the number of their cups on the data table in the “Me” column.
3. One cup is a control and will be used later in the activity. Do not do anything to this cup unless directed by your teacher.
4. Choose a partner in your group and exchange “body fluids” with this partner. One of you will pour your body fluid in the other person’s cup. Swirl the cup gently to mix the fluids. Then pour half of the fluid back into your partner’s cup. This exchange represents the first potential contact with the virus. Record the number of your partner’s cup under the column for “1st Exchange” in Table 1.
5. At a signal from the teacher, two students from each lab group should leave the group and form a new group with two new students, taking their cup with them. The two remaining students will be joined by new students from another group.
6. Choose a new partner from your new group and exchange “body fluids” as you did in Step 4. Record the number of the new partner under the
column for “2nd Exchange” in Table 1.
Record the number of your third partner under the column for “3rd Exchange” in Table 1.
8. Move back to you original group.
9. Using a pipette or dropper, place 3 to 5 drops of the virus detection solution into your “body fluid.” Observe your “body fluid” for a change in color. If it turns pink or red, the test is positive for a viral infection. If it remains clear or turns milky white, the test is negative, which means you are not infected with the virus.
10. All students who tested positive for the virus should give your exchange information to the teacher to record on the class data table. Copy the class information into Table 2.
Table 1 (Individual Data)
Me 1st Exchange 2nd Exchange 3rd Exchange
Table 2 (Class Data)
Positive for Virus 1st Exchange 2nd Exchange 3rd Exchange
11. Study the data table to try to determine which student was the original carrier of the virus. To check your results, each person should take their control cup and add 3 to 5 drops of the virus detection solution to the cup. Only one person should turn pink. This person is the “index case.”
Who is the “index case?” _______________________________
How do you know?
____________________________________________________________
____________________________________________________________
____________________________________________________________
____________________________________________________________
____________________________________________________________
____________________________________________________________
__________________________________________
Conclusion:
EXPLAIN, Part 3 Transparency
List of Diseases
Caused by
Bacteria
Caused by
Viruses
Caused by
Protozoan
Anthrax AIDS/HIV
Dysentery
Lyme Disease
*
Chicken
Pox
Malaria
*
Leprosy Small
Pox
Bacterial Meningitis
Yellow Fever
*
Strep Throat
Ebola
Tuberculosis SARS
Rabies
Influenza
West Nile Virus
*
Viral
Meningitis
Polio
Common
Cold
EXPLAIN, Part 3 Name ___________________________________
Handout Date
____________________________________
Microbes and Disease
(Use this sheet to record what you learn from class presentations.)
Disease Microbe Responsible
Treatment for the Disease
Statistic
AIDS
Anthrax
Dysentery
Influenza
Malaria
SARS
Strep Throat
Tuberculosis
ELABORATE, Part 3 Name ___________________________________
Handout Date
____________________________________
Bacterial Growth
Purpose: to practice determining the growth of bacteria given the time in which the bacteria reproduces and the number of bacteria that initially invade the organism.
Procedure: Create a visual or graph to accompany your response to each of the questions below.
1. A given bacteria reproduces (splits) every 5 minutes. If one bacterium invades the human body, how many bacteria will be present in the body after 3 hours?
2. A given bacteria reproduces every 3 seconds. If 2 bacteria are present at the onset of invasion, how many bacteria are present after 1 hour?
3. A given bacteria reproduces every 20 minutes. If 1 bacterium was present upon invasion, how long did it take for 128 bacteria to be present?
ELABORATE, Part 3 Name ___________________________________
Date ____________________________________
Bacterial Growth Answer Key
1. There are 180 minutes in 3 hours. If the bacteria split every 5 minutes, then there will be 36 reproductions in that time frame. This situation presents the problem 2^36 = 68,719,476,730 bacteria present after 3 hours. Students may choose to map out the reproductions as described in the initial demonstration by the teacher. For example the students could have mapped the following 1Æ 2, 2Æ4, 4Æ8, 8Æ16, 16Æ32, 32Æ64, 64Æ128, 128Æ256, 256Æ512, 512Æ1024, 1024Æ2048, 2048Æ4096, 4096Æ8192, 8192Æ16384, 16384Æ32768, 32768Æ65536,
65536Æ131072, 131072Æ262144, 262144Æ524288, 524288Æ1048576, 1048576Æ2097152, 2097152Æ4194304, 4194304Æ8388608,
8388608Æ16777216, 16777216Æ33554432, 33554432Æ67108864, 67108864Æ134217728, 13417728Æ268435456,
268435456Æ536870912, 536870912Æ1073741824, 1073741824Æ2147483648, 2147483648Æ4294967296, 4294967296Æ8589934592, 8589934592Æ17179869184,
17179869184Æ34359738368, 35359738368Æ68719476736. The first method is off by 6 bacteria because of the limitations of the number of places the calculator will hold (the answer is shown in scientific notation). Either method is acceptable.
2. There are 20 reproductions of this bacteria in that time frame; however, since the process starts with 2 bacteria, it is the same as starting with 1 and going through 21 reproductions. The equation would be
2^21=2097152. Again the mapping method could be used. This method should give the exact same answer because the calculator can hold 2^21 and give the exact answer.
3. The students will have to work backwards halving 128 and the resulting quotients until they reach 1 to figure out how many reproductions have occurred. Once it is determined that 7 reproductions have occurred, the students should then understand that each reproduction takes 20 minutes. Thus, 7 x 20 min = 140 minutes or 2 hrs and 20 min have passed.
4. The students will have to work backwards as in #3, halving 10,240 and the resulting quotients until they get to 20. Once it is determined that 9
EVALUATE, Part 3 Name ___________________________________
Handout Date
____________________________________
Compare and Contrast
I am investigating . . .
Vaccines and Antibiotics
How are they alike?
• _____________________________________________________
_____________________________________________________
• _____________________________________________________
_____________________________________________________
• _____________________________________________________
_____________________________________________________
• _____________________________________________________
How are they different?
Terms Used in Part 3
Active immunity
: protection against a disease acquired by
being infected with the pathogen that causes the disease.
Amoebic dysentery
: a disease that is caused by a
parasite. The protist amoeba that is found in contaminated
food and water.
Antibiotic
: a group of medicines used to kill or slow the
growth of bacteria that cause disease.
Antibody
: a chemical substance made by the body to help
destroy an invading pathogen.
Antimicrobial product
: is a substance that is designed to
kill microbes before they enter the body.
Carrier
: a person with a disease that they can pass on to
other organisms.
Contagion
: an infectious disease that can be transmitted or
spread from one organism to another.
Disease
: is any change that disrupts the normal function of
one or more body systems.
