Activity

Wind-blown seed models

Summary
Build seed models that are adapted for dispersion by wind. Attach tissue paper, feathers and other light materials to a foam ball, then test how far they can travel in a wind.
Science content
Biology: Features, Adaptations of Living Things (K, 1, 3, 7)
Biology: Life Cycles (2)
Earth/Space: Weather, Seasons, Climate Change (K, 1, 4, 7)
Lessons activity is in
Materials
  • foam balls
  • light materials with a large surface area e.g. tissue paper, tin foil, feathers, cotton balls
  • masking tape
  • small pieces of pipe cleaners
  • fan
  • optional: measuring tapes, to mark how far the seed designs go
  • optional:worksheet to record results
Procedure

Best run after looking at real wind-blown seeds, with wings and parachutes.
Discuss how seeds are light and wide, to catch the wind and move further away.

Show students the foam ball, and tell them that this is a seed. The other materials can be used to make the wings, parachute or other structures around the seed.
Stick the materials into the foam with tiny pieces of tape, or use the pipe cleaners to secure them.
The goal is to make a seed that stays in the air as long as possible (so make them light and wide).

To test how long a seed stays in the air: hold your seed above your head. Blow out as you drop the seed, to mimic the wind.
Compare your seed with its structures to a plain foam ball, to see if your seed moves further. Make sure to do three or more trials, to fairly compare how the plain seed and your seed with structures.
Even better, place a blowing fan in an area with space, which students can drop the seeds in front of.
Students drop the plain foam ball and their seed model at the same time in front of the fam.

Discussion:
Best design is (1) light so the force of gravity does not pull it down too fast, so it has time to go sideways; (2) wide so that it catches the wind and gets pushed sideways.

Real seeds are not "designed" like this, but different shapes arose by chance. The best ones gave a seed a greater chance of survival, and so their characteristics were passed to the next generation. This is called natural selection. (If one feature worked well, that seed was able to make more plants. The feature (or adaptation) is selected for.)

Video on the recently understood aerodynamics of a dandelion seed and why they stay aloft for so long: https://www.youtube.com/watch?v=N2UbaDV9O9Q

This activity inspired by:
http://www.earthrangers.org/wp-content/uploads/2016/05/NeedForSeed.pdf
https://www.scientificamerican.com/article/gone-with-the-wind-plant-seeā€¦
http://www.accessexcellence.org/AE/AEC/AEF/1995/taylor_seeds.html

Notes

Outside wind sounds a nice idea to do this lesson in, but is too variable to really compare the plain ball and seeds they make. Maybe take their models outside to play with in the wind at the end of the activity.

Add a sticky seed model: hold up a piece of fur. Give students pipe cleaner pieces to push into their balls, then throw at the fur to stick to it. OR they can use their hair. The ones with hooks hold better??

Grades taught
Gr 1
Gr 2
Gr 4
Gr 5