Lesson 4: Cottonwood Trees

Move That Seed!

Activity Developed by the University of Colorado Museum of Natural History

Description/Learning goals:

Participants will explore how seeds travel from their parent plant in different ways.

Participants can experiment with form vs. function and different textures such as smooth, sticky, etc.

Supplies:

  • Placemat or table
  • Velcro
  • Ping pong ball or floatable toy
  • M&Ms or Tootsie Roll Pop
  • Tissue paper

Activity Instructions:

  1. Create your different “seeds”:
    1. Go searching for some Velcro in your house- if you have some available to cut up use that, or find Velcro on shoes, lunchboxes, etc. The sticky side of the Velcro represents seeds like burrs that get caught in fur.
    2. For a seed that floats, use a ping pong ball, a floatable toy or something similar.
    3. For a wind dispersed seed, crumple up tissue paper or a piece of Kleenex.
    4. For the animal dispersed seeds, M&Ms and their colorful coating can show how digestion strips away part of the seed. You can use real fruit as well if you want to avoid candy.
  2. Make a hypothesis about how you could get these seeds far enough away from their parent plants (the placemat area).
  3. Take the soft side of the Velcro and catch the “burr”
  4. Act like an animal that likes fruit and eat the M&Ms or tootsie pop- sucking on the candy until the soft chocolate center is exposed. This is your exposed seed, and it can now grow. In real life, this would be exposed through poop.
  5. Blow on the placemat to move the tissue paper off the mat.
  6. Over a sink, pour water on the mat to move the floating seeds off of the mat. This can also be done as an experiment separately over the sink with all the items your child predicted would float away.

Science Concepts:

Plant Life Cycles:

Plants begin their life as seeds, which is usually covered in a tin shell that protects everything inside the seed, and keeps the seed from getting dried out.

Seeds are germinated by having the right combination of light, oxygen, moisture, and temperature. The seed pushes out little leaves to begin its life as a plant.

Plant Competition:

Seeds need to get farther from the parent plant to avoid competition

If the plant uses wind dispersal there’s a big chance the seed won’t go somewhere where it can actually grow. This is why there are so many seeds in a dandelion, to increase the chance of success.

Methods of Seed Dispersal:

Water: Some seeds are able to float, and can be carried away in a stream or rain to a new place to grow.

Gravity: Some seeds are heavy and round, which allows them to drop from the parent plant and roll away.

Wind: Some seeds have plant “wings” attached to their seeds to help them flutter away from the parent plant, and some have cotton like fuzz to help them get picked up by the wind.

Force: Some seed pods pop open and fling their seeds away from the parent plant. This is usually done when moisture inside the pod dries out, causing to pod to dry and break open at the seam of the pod.

Animals: Fruits and berries often are eaten by animals, along with their seeds. A few hours later, the animal poops out the seeds in a new location.

Early Learning 101:

Developing Logic and Reasoning:

Reasoning and Problem-Solving is the ability to recognize, understand, and analyze a problem. This is an important skill to develop during the 3-5 age range. Make predictions about what methods will move the seeds across the table.

Follow Up:

As you are working on assembling your “seeds” make a game of finding items in your house that could represent different seeds. For the floatable seed, what things in your house does your kid think could float or sink?

Talk through the thought process behind how to get each seed to work. Why does your child think one of the seeds will move?