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Plant Structure and Function

Grades: 6-8
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Lesson Summary


In this activity, students learn how the structure of different plant parts relates to their function. They begin by examining the fastening properties of Velcro® and comparing them to a method of seed dispersal called "hitchhiking." Wearing socks outdoors, they collect their own "hitchhiking" seeds (those that collect on the socks) and plant them. They explore the parts of a seed and what each part does, then work in teams to complete a jigsaw activity about other seed dispersal mechanisms such as wind and water. Next, students explore how the structure of a flower contributes to its pollination. Finally, they consider how other plant structures, such as tree and leaf shape, help the plant to carry out its life functions.


  • Explore how the structure of seeds and fruits contributes to seed dispersal
  • Understand the structure and function of the parts of a seed
  • Learn how flower structures contribute to successful pollination
  • Consider how other plant structures relate to their functions

Suggested Time

  • Two to three class periods

Multimedia Resources

Optional Resources


  • Velcro® fastener items brought in by students
  • A variety of seeds that are dispersed by different means:

    • Wind: dandelion, maple samaras
    • Hitchhikers (dispersed by animals): apple, cherries, and other fruits; burdock, teasel, tick trefoil, devil's sticktight
    • Water drifters: coconut, cranberries
  • Shoe box for each pair of students
  • Old socks, one pair per pair of students
  • Potting soil
  • Compound microscopes
  • Magnifying lenses
  • Peanuts or beans
  • Copies of the Plant Seed Adaptations Document

Before the Lesson

  • Ask pairs of students to bring in one item that contains a Velcro® fastener, a pair of old socks, and an empty shoebox.
  • Collect various seeds that show different dispersal mechanisms.
  • If using beans to explore seed parts, soak the beans in water overnight to soften the seed coat.

After the Lesson

  • Have students continue to water their sock seeds to see what kinds of plants grow.

The Lesson

Part I

1. Have students work in pairs to explore their Velcro® fasteners under the compound microscope. Ask:

  • How does the structure of Velcro® relate to its function?

2. Have students watch the Velcro video. Then show the Sock Seeds video. Ask:

  • What benefits do plants get by having seeds that stick to socks?

3. Have pairs of students do the Sock Seed activity (at home or on school grounds). Each student wears one sock. Ask students to bring in their socks with attached seeds.

4. Have students use a magnifying glass or microscope to examine the structure of a few of the seeds. Ask:

  • What function do seeds serve for plants?
  • What structures do they need to perform that function?

5. Tell students they will now explore the parts of larger seeds. Have students take apart the two halves of a peanut or a bean and draw what they see inside the seed. Show the Inside a Seed image to students. Point out that seeds contain the embryo, a food supply, and a protective seed coat.

6. Have student pairs plant their sock seeds in a shoe box, covering the seeds with potting soil as shown in the Sock Seeds video. Make sure students water the seeds on a regular basis.

7. Ask:

  • What other ways do plants disperse their seeds to new places? Have students view the Seeds Away collage.

8. Show students examples of different seeds. Have them guess how the seeds are dispersed based on their shape and structure and then explain their answer. For example:

  • Wind: dandelion, maple samaras
  • Hitchhikers (dispersed by animals): apple, cherries, and other fruits; burdock, teasel, tick trefoil, devil's sticktight
  • Water drifters: coconut, cranberries

Discuss the relationship between structure and function in all these seed examples.

9. Now ask students to read the Plant Seed Adaptations Document and answer the following question:

  • How did plants evolve these different methods for dispersing seeds?

10. Show the Floral Arrangements video. Discuss the relationship between structure and function in both flowers and the animals that pollinate them.

11. Ask students:

  • What are some other ways that plant structure relates to function? List ideas on the board.

12. Optional: Show the Shape of Things: Trees video. Discuss the following:

  • How does the shape of a tree and its leaves affect its ability to produce food?
  • What other functions of life must plants do to stay alive?
  • What structures allow them to do these functions?

Benchmarks for Science Literacy

Project Credits

Contributor: WGBH Educational Foundation-grayscale

Funder: National Science Foundation-grayscale

Producer: WGBH Educational Foundation-grayscale