What's Happening to My Body When I'm Sick?

Engage:

Learning Experience:

Ask the students to sign in on a sign in sheet at the front of the class to keep track of attendance.  (The pen used to sign in will have glow in the dark hand cream on it that you have already spread on the pen.)

Tell the class that a new infectious disease has been discovered that can be detected by black light.  Turn out the lights to see what students have the disease, visible on their hands. 

Hoped for student response:

Some students will have “glow in the dark” hands or other parts of their materials or body that they have touched. 

Questions:  

1.      How did you get the disease if you have it?

2.      How was the disease passed?

3.      Does the presence of the cream on your hands indicate that you have been infected?

4.      What variables would you use if you graphed the epidemic?

5.      What would the graph look like? Will it be linear, curved, or another graph?  Why?

Expected Student Response:

1.      First, they got the disease or were exposed to it by signing in.  Then they could have gotten the disease after it had spread to others or to surfaces in the classroom. 

2.      Touching the pen, signing in, touching each other or surfaces touched by others.

3.      Just because a person has been exposed to the disease does not mean they have been infected.  (Drive this point!)

4.      Number of people with the disease, number of people sick, number of deaths if a fatal disease.  Time is the other variable, which is independent.  The first variable, number of people is the dependent variable. 

5.      Straight line or curved.  If they answer either of the previously mentioned ways, they probably have not taken possibly immunity into account.  

Explore:

Learning Experience(s):

Today we will act out the spread of a disease that lasts for 2 days.

Each student is to receive one hand out and 4 post its: red, green, yellow and blue. 

Give each student 1 hand out and 4 post its (one each - green, red, yellow and blue).  These should be paperclipped together to make it easier to pass out. 

Tell the students that Green = immune, blue = infected, red = sick, yellow = recovering.

The first “victim” is chosen.   Give that student an extra “infected” card (blue post it).  Putting the red post it on will indicate that he or she is sick.   He/she will then give a blue post it to one other student within arms reach.  He or she takes the blue post it and puts it on. .    Record the data on the table to be visible on the overhead.  This is the end of day 1.

On Day 2, student 1 is recovering (yellow) and student 2 is sick (red).  Student 1 and 2 pass an infected post it to a student next to them.  Day is recorded from day 2. 

They will record the data on their handouts as the disease spreads. 

On Day 3, student 1 is immune, student 2 is recovering and students 3 and 4 are sick. Students 2, 3 and 4 pass blue post its to other students close to them in the class.  The simulation continues until no more students can be infected. 

Questions:  

1. If we graphed the number of sick people, what would this look like?  What would be different about the graph of the number of infected people or the one of the recovering people? 

2. How would you describe the graph of the number of immune people?

Expected Student Response:

1. The graph of the number of sick people goes up then down.  The graph for infected people will look like the graph of the number of sick people but will be offset a little bit.  The recovering people will look similar.

2. This graph is exponential. 

Explain:

The students are to graph the data with colored pencils.  Discuss in groups what you think the explanation of these graphs is. 

Questions:  

1.      Would you change your initial prediction of the graph, or were your predictions correct? 

2.      What accounts for the difference in the graphs?

3.      Did the disease ever reach epidemic numbers, meaning more than half sick or recovering? 

4.      What would the curves look like if half the population was already immune before disease was exposed? 

Students will produce a graph with 4 curves: one for infected, one for sick, one for recovering, and one for immune. The number of immune people goes up exponentially while at the same time the other go down.

Expected Student Response:

1.      This depends on their first response.    

2.      Sick people’s health eventually improves. . Immune people stay immune so the number will increase.

3.      This depends on the way the class does the activity.  More than likely, it will reach epidemic proportion.

4.      The number of sick people will be less and the overall graphs will remain the same.

Extend / Elaborate:

One half the class gets green post its and data sheets while the other only gets data sheets. 

Repeat the simulation. 

Record the data on the 50% immune sheet.

Ask students to graph their data.

Questions:

1. What difference do you see for the graph as compared to the trial in which no one was immune? 
2. What difference do you see in the graph of the number of people immune as compared to the trail in which no one was immune?
3. How are vaccines important?

Students will repeat the simulation and record their data.

Students will graph their data.

Hoped for response:

Students will see that the number of sick/recovering people is way less than when none of the population was immune to start with.  The number of immune people gets large.  Immunity prevents the disease from spreading.  Not everyone needs to be immune to keep an epidemic from occurring. 

Expected Student Response

6.      The curve should not be as longer.

7.      The curve goes up at a lower rate. 

8.      Vaccinations help keep too many people from becoming sick.  .