Activity 4: Why You Should Like Plants!

PDF versions of Activity 4: Why You Should Like Plants! are available in English and Spanish.

Coloring sheet: Medicines Come From Plants

Objectives: This activity emphasizes the importance of plants as organisms that have evolved to produce substances that are valuable as medicines to our society. Students will learn that almost all modern medicines are currently (or were in the past) derived from plant chemicals. They will also gain an understanding of the role of evolution in these chemicals’ existence as plant defenses.

Materials: copies of coloring sheet, markers or crayons


Who think plants are fun? (likely no one will say anything). Ok, but plants are very important, right? (wait for responses, probably someone will say “yes”) Why are they so important? (prompt them to say that we eat plants, maybe even say that we need plants to dress ourselves, etc). But plants are also very important because that is where a lot of the medicines we take come from! Explain that medicines that we use today, like pills and syrups, come from substances that we find in plants, and that in some places (actually, in most of the world), plants are still the only form of medicine that people use.

People discovered a long time ago that a lot of substances produced and used by plants are also good for humans, and figured out that they could be used to treat sicknesses. Today, we use them in modern medicines. For instance, did you know that aspirin comes from the bark of willow trees?

You know why plants produce medicines? Because plants get sick too. Often the plants produce these things to protect themselves against germs. In fact, plants have spent a very long time developing things like this to defend themselves and stay alive in a process called evolution.

And where do plants come from? Plants produce seeds, and those seeds grow up to be more plants. So if plants produce seeds throughout most of their life, which plant will produce more seeds, one that gets eaten or one that doesn’t get eaten? That’s right, the one that doesn’t get eaten. A plant that doesn’t get eaten as much will have more offspring that look like it. We say that adaptation favors plants that produce substances that protect them from being eaten because protected plants will live longer and produce more seeds.

A plant might produce a certain chemical that kills germs when they try to infect it. Because germs that attack plants are sometimes similar to those that attack humans, that same chemical can be used for humans too as part of a medicine. However, humans and plants are very different and not all substances that work for plants work for humans. Some things that are good for plants make humans sick!

[Now pass out coloring sheet and have kids color in in the handout of medicines coming from plants. Then hang up the colored handouts on the wall.]

Post-activity discussion questions:

  • Why would plants want to produce chemicals that we can use as medicines? In other words, how are those chemicals beneficial to them?
  • I asked you before we started why plants were important. Remember your answer? [remind them of their answer, if it didn’t involve medicine] What would you say now?
  • [to take it a step further] Does anyone know any reasons other than medicine that plants are important? I bet most of the food you eat and the products you use come from plants! What did you eat for breakfast this morning? What did you just color on? [give some other examples of common foods and materials]