The Scheme of Things

Okay, without making too much of a disturbance, look up and study the people that are in the same room that you are in right now. Be careful. Don't go and do anything real stupid and start drooling at the cutie sitting at the desk to the left of you. Just study those around you. Now, quietly take out a sheet of paper and make five observations about the physical features (hair or eye color, height, etc.) of five of your classmates or family members. Oh yeah, remember, don't be rude. This assignment is not meant as an excuse to make fun of anyone. When you have completed this part of the assignment, make five observations about yourself. Here is the question. Did any of the people that you observed have exactly the same features? Unless your subjects included identical twins, the chances are that the answer to this question is no.

There are many different types of plants, animals, and even people on this planet. We call this DIVERSITY or BIODIVERSITY. Because all animals, plants and people are diverse, scientists classify (divide) them into certain groups or categories based on how they are alike.

Even though animals are diverse, they are also the same in many ways. If you look at your classmates again do you notice things that make you all alike? Unless the guy sitting next to you in the red baseball cap is some type of alien plasma learning the "ropes" of being human, the answer to this question has to be yes. Because there are many things that make you the same, scientists have classified you into the same "group." You are humans and you are also mammals. We use classification systems in our everyday lives. Do you put your socks in the refrigerator? Of course not. You have a classification system in your room. At least most of you do. You put your socks in a specific place within that system.

Classification systems help us to make sense of the variety of things in our world. These systems are made by humans. They are usually based on physical similarities and chemical relationships between things.

Try this classification activity.

  • Remove everything from your desk.
  • Sort the material that was in your desk into categories based on how they are similar or work together.
  • List the groups that you have made.
  • Explain your classification (or grouped) system. Why did you group your materials the way you did?

You can try also this activity at your desk. In this activity you will practice grouping objects by their similarities and differences.

Collect pictures of insects and cut them out.

  • Group them by their similarities and differences.
  • Give a name to each of your groups.
  • Explain your method of grouping.
  • Why did you place certain insects in the groups that you did?
  • Can some of the insects be members of more than one group? Explain.

Scientists have already helped us classify Earth's animals and plants into categories. I'll bet you already know some of these groups. Look at the chart below and see what you already know. Do you know where your pet iguana fits in?


Scientists have already helped us classify Earth's animals and plants into categories. I'll bet you already know some of these groups. Look at the chart below and see what you already know. Do you know where your pet iguana fits in?






warm-blooded, fur/hair, live birth, vertebrate (with backbones,) lungs


don't loose their leaves, have pine cones


cold-blooded, vertebrate, scales


loose their leaves every year


live on & off land, vertebrate, cold-blooded, lay eggs, gills




feathers, vertebrate, lay eggs, wings, warm-blooded




gills, vertebrate, live in water, lay eggs, cold-blooded




invertebrates (without backbones,) exoskeleton, 6 legs



The above chart is just a small part of the system which scientists use to group the great diversity of living things in our world. Scientists have classified plants and animals into categories as you have just learned. And as you have already know, they also classify parts of the world. A biome, for example, describes a zone (or land area) on the Earth with a similar climate, and plant and animal life. Living in each biome are the plants and animals that can survive and thrive in that area.

Clean It!

Use the information above to classify the materials in your own bedroom. Throw the junk in the garbage and neatly organize your belongings. Think of it this way. You will be practicing "real science" and making your parents very happy at the same time. Who knows what kind of praise or award might be awaiting you for having a clean and organized room? In addition, you may get some "brownie points" for calling it a homework assignment. Go for it!

By clicking on the ant above, you can find out all about the biodiversity in your own backyard. After studying the information on this site, use a magnifying glass to identify and classify the abundance of life in your own backyard. Remember, you can make up your own system to group the life that you discover. Have fun, but remember, some bugs or spiders may bite!
By clicking on the tree above, you can go to an Internet site containing tons of information about the diversity of life on our planet. Use this site to make a brochure about one group of living things. Remember there are millions of living things on Earth and not all of them are plants or animals. Be creative and find a group that is unique.

Are you ready to see how well you have learned about classification? If you click on the guy to the right, you will be taken to a Utah Diversity Quiz. When you get to the page, click on "4th Grade Classifying Vertebrates." Good luck!

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Updated August 7, 2001 by: Glen Westbroek

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