You are here

Activity

Seed germination and gravity

Summary: 
Bean seed are planted at different angles, to test which way the roots and shoots grow. Done as a demonstration.
Science content (2016 curriculum): 
Biology: Features, Adaptations of Living Things (K, 1, 3, 7)
Biology: Life Cycles (2)
Biology: Sensing, Organ Systems (4, 5, 6)
image
image
Lessons activity is in: 
Materials: 
  • Jar for each set up
  • coffee filter
  • Paper towels
  • Water
  • 3 or 4 large bean seeds (e.g. broad bean) per jar
Procedure: 

What might affect the direction that roots grow?
(Students might suggest water, darkness....)

Put some beans in a jar at different angles to test which way the root and shoot grows each time:
Make a ring of coffee filters paper towels inside the jar, and stuff the centre with more paper towels.
Add water to the paper towels until they are wet and there is a small puddle at the bottom of the jar.
Push the bean seeds between the coffee filter ring and the glass jar wall, to hold them in place, each at a different angle, spread out around the jar.

One week later:
What can we conclude about something other than water and air (and darkness) that seed germination is sensitive to? Gravity.
Which way up should we plant a seed? (Doesn’t matter)

Results:
The roots always grow downwards, then the shoot upwards.
The seeds are uniformly wet and exposed to light, so they use gravity to determine which way to grow.

Notes: 

Apparently, this can be set up with a pin through the bean.
The lid can be rested on to keep water evaporation to a minimum, while allowing air to get into the jar.
This is a good activity to show the results of after other germination factors have been determined.

Grades taught: 
Gr 3
Teacher: 
Ingrid
Tracy Povey
Teaching site: 
General Gordon Elementary