Diseases are things that make us feel sick or unwell. There are many different kinds of diseases, like the the common cold, diabetes or even more serious diseases like cancer. Scientists study diseases to try to find cures and treatments to help people feel better.

The activity we will be doing today will simulate the spread of an infectious disease. A simulation is a simplified demonstration of how an infectious disease can spread through a population. Our simulation will show how one person who is infected with a disease can infect other people, who in turn infect others.

How does one sick person lead to hundreds in just a few days? Infectious diseases spread through contact. Each infected person passes the illness to new people. Those people then infect others.

You simulate this chain reaction by mixing solutions in cups. Only one cup starts out "infected." After two rounds of sharing, you add an indicator that turns infected cups pink.

You graph the number of infected people after each round. The pattern matches exponential growth (doubling over and over). A single bacterium doubles the same way and can reach one million in just ten hours.

Similarities between the Spread of an Infectious Disease and Population Growth

How Does an Infectious Disease Spread? 

An infectious disease is any disease caused by germs that can be spread from one person to another. Germs include viruses, bacteria and protozoa. What are some
infectious diseases? 
 
What are some diseases that are not infectious?

This activity will simulate the spread of an infectious disease. A simulation
is a simplified demonstration of a real biological process. Our simulation will
show how an infectious disease
can spread from one infected person to other people, who in turn infect others.

Instructions

1. Your teacher will give everyone a cup filled with a clear solution. This solution represents your body. Only one person in the class will have a cup that has been “infected”.

Obviously, you should not drink from the cup. (In laboratory activities you should never drink
or eat anything unless your teacher tells you that it is safe to do so.)

2. In this part of the activity, you will interact with two other students. To interact with another student, pour all of your solution into your partner’s cup. Then have your partner pour all of the mixed solution back into your empty
cup. Finally, pour half of the mixed solution back into your partner’s empty cup.

Wait for the signal from your teacher, and then move to
another part of the classroom and interact with a second student. After you have
finished your second interaction, return to your seat.

Estimate how many people you think will be infected.

3. Your teacher will come around and put an “infection indicator” in your
cup. If you have exchanged solutions with the original infected person or someone else after they became
infected, you are now infected and your solution will turn pink. 
If you have not exchanged solutions with anyone who was infected, your solution will not turn color.

4. Repeat another set of interactions, again beginning with only one student with
an infected cup. This time there will be three rounds of interactions. For each
interaction, be sure to move to a different part of the room with different students.
 
After the teacher has come around with the indicator, write down how many people were actually infected.

 5. Now graph how an infection spreads with increasing numbers of interactions.

First, plot a point to indicate that one person was infected before any interactions. How many people would be infected after just one interaction?

Next, plot the number of people who were infected after two interactions (from 3 on page 1) and the number of people who were infected after three interactions (from 4 on pages 1-2).

 Our simulation showed the way a disease
could spread if the spread of disease depends on person-to-person
contact.

Population Growth

There are interesting similarities between the spread of infectious
diseases and population growth, e.g., the increase in the number of
bacteria, plants or animals in a population. For example, in a
growing population of bacteria, each bacterium can give rise to two new bacteria
after about 30 minutes. This results in a doubling of the number of bacteria
every 30 minutes, which is similar to the doubling in the
number of infected people after the first and second rounds of disease-spread interactions.

Suppose a single bacterium is placed on an agar plate and the number
of bacteria in the population doubles every 30 minutes. How long do you think it
would take before there would be 1000 bacteria?

To calculate how long it would actually take for the single bacterium to
multiply to form a colony of 1000 bacteria, fill in the number of bacteria at
each time in a table with the following rows:
- bacterium at the beginning
- bacteria after 30 minutes
- bacteria after 1 hour
- bacteria after 1 hour and 30 minutes
- bacteria after 2 hours
- bacteria after 2 hours and 30 minutes
- bacteria after 3 hours
- bacteria after 3 hours and 30 minutes
- bacteria after 4 hours
- bacteria after 4 hours and 30 minutes
- bacteria after 5 hours

How long would it take for the population of bacteria to increase from 1 bacterium to 500 bacteria?

How long would it take for the population of bacteria to increase from 500
bacteria to 1000 bacteria?

Notice that, when a population doubles every 30 minutes, the number of bacteria in the
population increases faster and faster as the population gets larger.

This kind of population growth is called exponential growth.

To see what exponential growth looks like in a graph, use the data from the
above table to plot the number of bacteria on a graph where the x-axis is every hour.

If exponential growth continued for 10 hours, the original single
bacterium would increase to a population of over one million bacteria. This
illustrates how exponential growth can result in very rapid increase of population size.


Infectious Disease and Exponential Growth

How does an infectious disease spread?

<h1><strong>1000 Science Fair Project Ideas by Subject</strong></h1><p>Looking for a science fair project idea? Each of our science fair project idea has complete instructions with video. Get ideas for your science projects, find extra resources for your class' scientific projects, or try a fun experiment at home! It doesn't matter what grade you're in, there's something for everyone!</p><p>You can find your perfect science fair project from the different science subjects below or from our <a href="https://www.all-science-fair-projects.com/category0.html#bottom">science fair project idea lists!</a></p>

<h2>Science Fair Project Idea Lists</h2><p>Looking for other ways to find good ideas for science fair projects? Check out these lists of science projects!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h3>Easy Science Fair Projects</h3><p><img src="/images2/flex/176_popular 2 (2).png" data-size="100" data-float="left" style="width:100px; float:left">Explore the exciting world of science with an easy science fair project that you can do at home using simple materials. Any one of these easy project ideas will teach you important scientific concepts and help you have fun while learning. An easy science fair project is a great way to introduce the wonders of science to kids and adults alike!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><ul><li><p>Changing the Color of Flowers</p></li><li><p>Baking Soda Volcano</p></li><li><p>Swimming Raisins</p></li><li><p>Egg in Vinegar</p></li><li><p>Color of Skittles Experiment</p></li><li><p>Jumping Rice Krispies</p></li><li><p>Mixing Colors of Light</p></li><li><p>Camouflage and Hide</p></li><li><p>Light and Dark on Seed Germination</p></li><li><p>Make a Parachute</p></li></ul><p>More science project details at <a href="https://www.all-science-fair-projects.com/science_fair_project_list/12">Easy Science Fair Projects <strong>→</strong></a></p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h3>The Top 10 Best Science Fair Projects</h3><p><img src="/images2/flex/177_popular 2 (3).png" data-size="100" data-float="left" style="width:100px; float:left">To find the best science fair project for you, we've picked the best science projects from 10 different science categories, all with very interesting topics. If you're looking for more science projects at another difficulty level or topic, you can explore science fair project ideas by grade level at the top of this page!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><ul><li><p>Jet Lag in Hamsters (circadian rhythm, Biology science fair project)</p></li><li><p>Egg with Vinegar (acid-base reaction, Chemistry science fair project)</p></li><li><p>Galileo's Inclined Plane Experiment (acceleration, Physics science fair project)</p></li><li><p>Plant's Favorite Color for Photosynthesis (Photosynthesis, Botany science fair project)</p></li><li><p>Color and Taste (color perception, Psychology science fair project)</p></li><li><p>Does Dog Saliva Kill Bacteria? (antibacterial, Microbiology science fair project)</p></li><li><p>Decomposing Plastic Spoons (biodegradable materials, Environmental Science science fair project)</p></li><li><p>Super Hero Egg Shells (structural engineering, Engineering science fair project)</p></li><li><p>Music Math: Playing Notes with Equations (music, Math science fair project)</p></li><li><p>Temperature's Effect on Seawater (climate change, Earth Science science fair project)</p></li></ul><p>More science project details at <a href="https://www.all-science-fair-projects.com/science_fair_project_list/13">Best Science Fair Projects <strong>→</strong></a></p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h3>Cool Science Fair Projects</h3><p><img src="/images2/flex/178_popular 2.png" data-size="100" data-float="left" style="width:100px; float:left">Get ready to be amazed by super cool science projects that you can do right at home! With just a few simple things, you can be fascinated by science and have tons of fun with these popular science projects!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><ul><li><p>Explosive Elephant Toothpaste</p></li><li><p>Egg in Vinegar</p></li><li><p>Electrifying Lemon Battery</p></li><li><p>Making Oobleck: Liquid or Solid?</p></li><li><p>Egg Drop Project</p></li><li><p>Colors of Skittles Experiment</p></li><li><p>Cloud in a Bottle</p></li><li><p>Baking Soda Volcano</p></li><li><p>Egg in a Bottle</p></li><li><p>Plastic Milk</p></li></ul><p>Project details and more cool science projects at <a href="https://www.all-science-fair-projects.com/science_fair_project_list/1/Popular_Science_Experiments_At_Home">Popular Science Fair Projects <strong>→</strong></a></p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h3>One-Day Science Fair Project Ideas</h3><p><img src="/images2/flex/172_popular 2 (1).png" data-size="100" data-float="left" style="width:100px; float:left">Quick experiments can be a great option for a science fair project. In this list, we've highlighted one-day science fair project ideas for elementary school (easy), middle school (medium), or high school (hard). These experiments are fast and easy to do, but the science topic packs a punch!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h4>Acid-base reactions: Mixing acids with bases quickly makes carbon dioxide gas!</h4><ul><li><p><a href="https://www.all-science-fair-projects.com/project830.html"><strong>Rocket Film Canisters (easy) </strong></a>Make a rocket fly sky high with just baking soda and vinegar!</p></li><li><p><a href="https://www.all-science-fair-projects.com/project829.html"><strong>Make Your Own PH Indicator (medium) </strong></a>Learn how to make your own acid-base indicator using red cabbage and use it to test different fluids!</p></li><li><p><a href="https://www.all-science-fair-projects.com/project1327.html"><strong>Testing Antacids (hard) </strong></a>Find out which antacid can neutralize the most acid and get relief from heartburn and gastritis!</p></li></ul><h4>Chromatography reactions: Separating out colors as liquid moves through the paper!</h4><ul><li><p><a href="https://www.all-science-fair-projects.com/project826.html"><strong>Colors of Skittles Experiment (easy) </strong></a>Did you know that some Skittles have a secret rainbow hiding inside them?</p></li><li><p><a href="https://www.all-science-fair-projects.com/project678.html"><strong>Uncovering Fall Colors (medium) </strong></a>Have you ever wondered why leaves change color in the fall? Let's find out by using chromatography to separate the colors of a green leaf!</p></li></ul><h4>Heat reactions: Heat speeds things up!</h4><ul><li><p><a href="https://www.all-science-fair-projects.com/project274.html"><strong>Which Candle Burns the Fastest? (easy) </strong></a>Do you want to find out which color candle burns the fastest?</p></li><li><p><a href="https://www.all-science-fair-projects.com/project1291.html"><strong>Fire-Resistant Balloons (medium) </strong></a>Ever wondered if a balloon filled with water can withstand fire?</p></li><li><p><a href="https://www.all-science-fair-projects.com/project475.html"><strong>Can Peanuts Heat Water? (hard) </strong></a>Have you ever wondered if peanuts have enough energy to heat up water?</p></li></ul><p>Project details at <a href="https://www.all-science-fair-projects.com/science_fair_project_list/15/Quick_Science_Fair_Projects_You_Can_Do_In_A_Day">Quick Science Fair Projects →</a></p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h3 style="text-align: start"><strong>Testable Questions for Science Projects</strong></h3><p><img src="/images2/flex/173_popular 2.png" data-size="100" data-float="left" style="width:100px; float:left">A testable question is a question that we can answer through a science experiment. To do this, we do a control experiment, then we change one thing in the experiment to see how it affects what happens. This is how we can discover the answer to our question!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><ul><li><p>What makes a cloud form?</p></li><li><p>Can drink and food taste different just by changing its color?</p></li><li><p>Does the color of light affect photosynthesis?</p></li><li><p>Does temperature affect seed sprouting?</p></li><li><p>What makes popcorn pop?</p></li></ul><p>More <a href="https://www.all-science-fair-projects.com/science_fair_project_list/14">testable questions with their science projects <strong>→</strong></a></p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h2>Science Fair Project FAQ</h2><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h3>What are some hands-on ways to find inspiration for my science fair project?</h3><h4>Science museums</h4><p><img src="/images2/flex/124_7.png" data-size="100" data-float="left" style="width:100px; float:left">Science museums are great places to explore if you're looking for inspiration for your next science fair project or just want to learn more about science. Science museums, natural history museums, space museums, and discovery museums are all great places to do that! You can discover all sorts of interesting things about science and find cool project ideas for science fairs.</p><p>There may be free admission days or free passes to a science museum near you! Check your credit card for offers, your local library for free museum passes, and nearby science museums for free entrance days.</p><p>So what are you waiting for? <a href="https://en.wikipedia.org/wiki/List_of_science_museums">Find a science museum near you</a> and prepare to be awed by all that you can learn there!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h4>Look around and observe</h4><p><img src="/images2/flex/117_5.png" data-size="100" data-float="left" style="width:100px; float:left">Do you know how scientists start their cool projects? They often look around and notice things that are interesting or make them curious. Then they start doing an experiment! You can do the same! Look around your school, home, or community. Is there anything that catches your attention and makes you curious? Maybe you notice something interesting or a problem that people are facing. This could be a great starting point for your science fair project!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h4>Try an Easy Science Project!</h4><p><img src="/images2/flex/144_easy square.png" data-size="100" data-float="left" style="width:100px; float:left">These science projects are easy and fun to do. You may discover a simple experiment that sparks your interest and inspires you to do more experiments, turning it into a science fair project! Check them out at <a href="https://www.all-science-fair-projects.com/science_fair_project_list/12">Easy Science Fair Projects <strong>→</strong></a></p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h3 style="text-align: start"><strong>How do I start a science fair project?</strong></h3><p><img src="/images2/flex/199_science coach.png" data-size="100" data-float="left" style="width:100px; float:left">No matter if you're in high school, elementary or middle school, science fair projects are a fun and unique way to discover science by asking a question and doing a science project. We'll help you find a science fair project idea and guide you through the process of doing and presenting your science fair project with <a href="https://www.all-science-fair-projects.com/science_fair_projects_coach/science-project-coach.html">Science Fair Coach's Science Fair Project Guide</a>.</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h3>What should I do after I have a science fair project idea?</h3><p><img src="/images2/flex/143_intro science fair.png" data-size="100" data-float="left" style="width:100px; float:left">If you have a science fair project idea, Science Fair Coach can help you turn it into a full science fair project! Starting at the <a href="https://www.all-science-fair-projects.com/pgpage/4">Introduction to Science Fairs</a>, check out the section on <strong>How to do a science fair project</strong> for a step-by-step guide!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><p><img src="/images2/flex/203_compared to scientific method.png" data-size="100" data-float="left" style="width:100px; float:left">We'll guide you through every step of the <a href="https://www.all-science-fair-projects.com/pgpage/5">scientific method</a>, from designing and conducting your experiment to collecting and analyzing your findings.</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><p><img src="/images2/flex/202_engineering design process.png" data-size="100" data-float="left" style="width:100px; float:left">If you're working on an engineering project, you can head over to <a href="https://www.all-science-fair-projects.com/pgpage/9">The Guide to the Engineering Design Process</a>.</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><p> <img src="/images2/flex/150_science fair poster.png" data-size="100" data-float="left" style="width:100px; float:left">Finally, we'll help you showcase your results on a <a href="https://www.all-science-fair-projects.com/pgpage/7">science fair board</a> for others to learn from and enjoy.</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h3 style="text-align: start"><strong>How do I make a science fair board?</strong></h3><p style="text-align: start"><img src="/images2/flex/150_science fair poster.png" data-size="100" data-float="left" style="width:100px; float:left">Your science fair board is where you show off your science fair project for everyone to see and learn from. With <a href="https://www.all-science-fair-projects.com/science_fair_projects_coach/science-project-display-board-6a.html">Science Fair Coach's step-by-step guide</a>, you can make sure your science fair board stands out and impresses at the science fair!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><hr style="clear:both; border-style:dotted" data-marker="clearFloat"><h3>Where can I find a science fair competition?</h3><p><img src="/images2/flex/179_Intro Science Fair Projects 32.png" data-size="100" data-float="left" style="width:100px; float:left">Science fair competitions are an excellent opportunity to explore science. One of the of the premier science advocacy organizations, the Society for Science, is associated with more than 400 science fair competitions in almost every US state, as well as over 70 other countries, regions, and territories. You can find out if there's a <a href="https://findafair.societyforscience.org/">Society of Science affiliated science fair</a> near you!</p><p>The <a href="http://physics.usc.edu/~gould/ScienceFairs/">The www Virtual Library: Science Fairs website</a> also has a collection of science fairs from all over the world, as well as national, state, regional, local, and virtual competitions!</p><hr style="clear:both; border-style:dotted" data-marker="clearFloat">

Medicine and health are about understanding how our bodies work and how we can keep healthy. Doctors identify and treat diseases, and commonly-occurring discomforts such as allergies and skin issues. Nutrition plays a crucial role in maintaining good health.

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1000 Science Fair Projects with Complete Instructions

Infectious Disease and Exponential Growth

Hypothesis

Method & Materials

Results

Why do this project?

Also Consider

Full project details

Related Science Fair Project Ideas