This is a fun cross-curricular lesson that works well for both math and biology classes. To begin with, introduce the following problem:

Tell students you are going to do a lab to model the spread of disease. You will need the following:

To begin the activity students should put a 2 drop sample in the first well of their row. Then have students pair up with someone in the class. Instruct students to mix their solutions by pouring them together and then dividing the solution equally between each cup. Once the solutions are mixed students should take a sample and place it in the second well of their row. Students should repeat this process four more times, making sure they do not pair with the same person twice.

- Dixie cups
- Water
- .01M NaOH
- Phenolphthalein (indicator)
- 24-well reaction plates (1 for each group of 4 students)
- Disposable transfer pipettes (1 for each student + 1 for the phenolphthalein)

To begin the activity students should put a 2 drop sample in the first well of their row. Then have students pair up with someone in the class. Instruct students to mix their solutions by pouring them together and then dividing the solution equally between each cup. Once the solutions are mixed students should take a sample and place it in the second well of their row. Students should repeat this process four more times, making sure they do not pair with the same person twice.

Collect the student's droppers and discard them. Each group should now be given a cup with a small amount of phenolphthalein and a new dropper. Allow one student at a time to test their group's samples with a drop of the indicator. Instruct students to test one column at a time in order to study the progression of the disease after each stage of student contact. After each column is tested, ask each group to report the number of students "infected" and create a chart to record results. Students should then be instructed to graph the data. It should be fairly obvious that the data trend is not linear. Optional activities include:

- Finding an equation for the data and applying it to solve the initial problem;
- Further discussion of exponential growth.

After students are finished with the lab activity, introduce the game, Plague Inc. The game is $0.99 on iTunes. Click on the app image to find out more information.

Students should choose

Once students accumulate enough points, they can mutate their disease according to Transmission, Symptoms, or Abilities. This is an excellent opportunity for more in-depth discussions about various biological topics. As well, direct students to the

Students should choose

**Bacteria**as their*Plague Type*, and**Casual**as the*Game Difficulty*. Students then have to decide where to start their plague. Discuss conditions that are conducive to spreading diseases. Once students select a country, they have to begin collecting*DNA Mutation Points*by popping DNA bubbles.Once students accumulate enough points, they can mutate their disease according to Transmission, Symptoms, or Abilities. This is an excellent opportunity for more in-depth discussions about various biological topics. As well, direct students to the

*World*button to monitor the disease transmission. Students will find a graph of the world population under*Data and*should revisit this periodically throughout the game.