Watch the Bozeman Science video " Planning and Carrying out Investigations"

• Think about a question that you have about a disease.

• How could you design an experiment that would answer that question?

Use a simulation to conduct an inquiry on how disease is transmitted in a population.

• Link to simulation

This activity allows the user to model a population of people susceptible to a disease, infected with the disease, and recovered from the disease. It demonstrates what happens in the real world when people infected with a contagious disease interact with others in their community.

Try experimenting with different characteristics of the disease like infection rate, initial population, etc. to see what happens to the population with different parameters. Look at the graphs that are produced by clicking on the graph button. Compare your results at a specific number of days as indicated on the x-axis of the graph.

1. Do the results change when the parameters change?

2. Are they always the same with the same parameters?

3. What does this tell you about how real-world populations react to disease?

Use this worksheet to guide you through the simulation.

• Worksheet and guidance for the inquiry

Humans are not the only organisms that can spread disease. Some diseases, such as the bubonic plague and malaria are spread by vectors. A vector is an organism (other than a person) that spreads disease-causing germs usually without getting sick itself. Rats, ticks, bats, mosquitoes, and fleas can act as vectors for various human diseases. Ticks, for example, spread Lyme disease. That’s why it’s important to wear long sleeves and pants to avoid picking up ticks when hiking in some areas

View these videos to learn more

• How do diseases jump from animals to Humans?

• Here is how Scientists think Coronavirus spreads from Bats to People

Scientific discoveries often follow the development of new tools and technologies. This is certainly true in the case of infectious diseases. In the 1890s, researchers Alexandre Yersin and Shibasaburo Kitasato independently used the microscope to identify the cause of the bubonic plague. Compound microscopes—microscopes that use more than one lens—had been invented around 1595. These first microscopes usually magnified objects only 20–30 times their original size. But as you will learn in the next few activities, even this level of magnification was enough to discover a world of new scientific ideas. By 1840, Italian physicist Giovanni Amici had invented the oil-immersion microscope which could magnify objects 6,000 times. In most middle schools, the highest level of magnification is usually about 400 times. Today, the transmission electron and scanning electron microscopes can magnify objects over 40,000 times!

Learn about microscopes and how to use a light microscope by viewing this video.

Use this student worksheet to guide you through drawing an image as it is seen through a microscope.

How does the microscope change the image that you see in a microscope?

Additional resource - Introduction to the Microscope - has images of the letter e that you can use for your lab drawing.

View these two videos

• 10 cool things to look at under a microscope

• Animation - What happens when you get Coronavirus?

The microscope is one important tool used by scientists to study living things.

• What other tools are used by scientists? Think about what you have learned about scientists studying disease and how it is transmitted. List three tools that were used by scientists and describe the kind of information they can help scientists collect.

• Why are tools important to scientists and how do they help advance what we know about disease?

• Why is knowing about the tools that you are going to use in an experiment important when you are planning an investigation?