Title Fizzies Virus Overview This is a simulation activity on how disease spreads. I use it with 7th graders (12 year olds), but it can be used with any age group. It takes 2 class periods. Subject(s) Science Grade Level(s) Grade 6 Suggested Time 1.45 Hours Materials virus, carrier, epidemic, communicable disease, vaccination, immunity, pathogen, infected, a list of diseases Objectives Students will be able to: describe how disease spreads. trace a "disease" to the first "infected" person Materials One small cup (7 oz.) per student Water approximately 3 oz. per student 3 oz. of hydrogen peroxide (drugstore/home strength) Sharpie Marker 4 oz. bleach (in a small wide mouth plastic container) Medicine dropper (for bleach) On-Line Resources Center for Disease Control http://www.cdc.gov National Institute of Health http://www.nih.gov Web MD http://www.webmd.com Off-Line Resources Books on microorganisms especially those with large size photos. Preparation Do the following out of student sight. Number the 7 oz. cups on the side. Pick a cup other than #1 and pour 3 oz. of hydrogen peroxide into it. Write down the cup number where your students will not see it. Put 3 oz. of water in the remaining cups. (The extra room will help prevent spills.) Motivation I ask my students to brainstorm a list of diseases and then we talk about their lists. I then tell them I have discovered a new disease, the "Fizzies Virus." I remind them proper lab procedures: take extra care when moving around the room, chairs are under the tables, they should not taste the liquid, the proper way to smell the liquid, etc. Activity Part 1: Students have their paper numbered 1 - 3. They are to decide who to exchage with. Person A of the pair carefully pours their entire cup into Person B's cup. Person B carefully pours about half of the liquid back into Person A's cup. They write down on their paper who they exchanged with in order. Each student repeats the procedure twice more. When they finish they go back to their desks and sit down. (Please tell the students how important it is to follow these directions. They SHOULD NOT exchange with the same person twice.) Part 2: The teacher goes to each student and drops 2-4 drops of bleach into their cup. If it fizzies, the cup is infected. (I say the cup instead of the child. This prevents any teasing.) The liquid is safe enough to be poured down a sink. The students with "infected" cups are listed on the board or overhead. I have my students copy this information. (I've found that most of the students want to have an "infected" cup!) Conclusion The students with the "Fizzies Virus" cups are asked to name the students in order that they exchanged with and those names are written down. The class tries to detect who had the original "infected" cup. This will look like a web/graphic organizer. The teacher may have to guide them on to do this logically. It is sometimes easier to see, who was not the first "infected". Home Work Extension Students may take the information and work it out at home. Next Day Extension Explain how this is similar to real life, but infection is not limited to 3 people each time. Sometimes people forget where they have been and who they have been around. Sometimes they get well and then are reinfected. They may also not tell the truth because they think they will get in trouble, just like students who do not follow directions.