In this lesson, students learn about the characteristics that distinguish living things from nonliving things. By examining video clips and still photographs of a variety of objects and organisms, students gather evidence and develop criteria to decide if something is living or nonliving.
- Develop criteria to decide if something is living or nonliving
- Classify things as living or nonliving, based on those criteria
- Recognize that living things grow, reproduce, and need food, air, and water
Grade Level: K-2, 3-5
This lesson is appropriate for students in all elementary grades.
- Two 40-minute blocks
- Is It Alive? QuickTime Video
- Living and Nonliving JPEG Image
- Animals on the Go QuickTime Video
- Animals Making a Living QuickTime Video
- What Do Animals Eat? QuickTime Video
Use these resources to create a simple assessment or video-based assignment with the Lesson Builder tool on PBS LearningMedia.
- Handout: Exploring the Characteristics of Living Things PDF Document handout
Before the Lesson
- Make an overhead transparency of the handout.
- Make a copy of the handout for each student.
Young children often have difficulty characterizing things as living or nonliving. For example, they tend to describe anything that moves as alive. They also do not yet understand the cycle of life (birth, growth, death), and therefore classify as nonliving anything that has died. In science, living is used to describe anything that is or has ever been alive (dog, flower, seed, road kill, log); nonliving is used to describe anything that is not now nor has ever been alive (rock, mountain, glass, wristwatch). Over time, students will begin to understand that all living things grow, breathe, reproduce, excrete, respond to stimuli, and have similar basic needs like nourishment. Older students may even realize that all living things are made up of cells.
1. Ask each student to name one living thing and one nonliving thing. Write all their contributions on easel paper or on the chalkboard, under the column headings "Living" and "Nonliving".
2. Tell students that they will be studying living things, or organisms. Have students reflect on the list of organisms they generated and think about all the features that make organisms "alive." Have them brainstorm answers to these questions:
- What are some characteristics of living things?
- What are some characteristics of nonliving things?
- What makes living things different from nonliving things?
If your students are not reading or writing yet, use pictures or symbols to represent written text.
Write all ideas down. This student-generated list can be used as a reflection tool throughout the unit. Avoid telling students the correct answers.
3. Explain to students the scientific definition of living (anything that is or has ever been alive) and nonliving (anything that is not now nor has ever been alive). Remember that the difference between nonliving and dead can be confusing to youngsters. Give an example of something that is dead but still classified as living, such as a log.
4. Distribute copies of the handout Handout: Exploring the Characteristics of Living Things (PDF). Use an overhead transparency of the handout to show students how to fill in the Characteristics of Life column headings based on the list the class generated in Step 2.
5. Working in pairs, have students view examples of living and nonliving things from the Is It Alive? video and theLiving and Nonliving stills collage. Have them classify each example as living or nonliving and record the name of the object or organism under the appropriate heading on the handout. Then have students indicate which characteristics of life each example exhibits by putting a check in the appropriate column. (For very young children, you can explore examples of living and nonliving things by displaying the stills on a large screen. To simplify the task of recording their observations, young students can draw pictures or use symbols to represent the things they examine.)
You might want to choose one example and model the process of scientific inquiry for students. Ask questions (Does this example reproduce? Does it grow?), make observations (The river is definitely moving.), and carefully record the results. Point out the importance of thinking like a scientist.
As students explore the examples, they may discover other characteristics of life they hadn't thought of earlier. Encourage them to add these characteristics to the chart.
6. Have students reflect on their findings by discussing the following questions:
- What characteristics did ALL of the living things have in common?
- Did any nonliving things possess some of the same characteristics as living things? Which ones?
- How were the living things different from the nonliving things?
7. Assess students' understanding (and identify possible misconceptions) by asking:
- Are all things that move "alive"? Have them defend their opinions by referring to the results of their explorations.
- What kinds of nonliving things move?
Again, show them the clip of the moving cars, the running river, or the dripping icicle in the Is It Alive? video and ask:
- How is the movement of living things different from the movement of nonliving things?
- Do all living things move?
If students say yes or are unsure, again show them the picture of the grass or plant or the clip of the coral. Then show them the video Animals on the Go and ask:
- What kinds of living things move? What kinds don't move?
- Do plants move?
- Why do living things move?
Show them the Animals Making a Living video to help them answer this last question.
8. Show students the What Do Animals Eat? video. Ask:
- Do all living things eat?
- Plants don't eat but they need energy. Where do they get it?
9. Anticipate questions about growth. For example, icicles "grow," yet they aren't alive. Explain that all living things grow some time in their lives, but that some nonliving things seem to get bigger too. For this reason, growth cannot by itself be used to classify something as living.
10. End the lesson by asking students whether they want to make any changes to the original list they made of the characteristics of living things.