Activity

Seed dissection

Summary
Dissect a large bean seed to find the embryonic root and shoot.
Look closely at a dandelion seed with its attached parachute.
Science content
Biology: Features, Adaptations of Living Things (K, 1, 3, 7)
Biology: Life Cycles (2)
Science competencies (+ questioning + manipulation + others that are in every activity)
Planning/conducting: data collection/recording (K up)
Processing/analyzing: experiencing and interpreting the local environment (K up)
Soaking the beans a couple of days before the class
Bean seed root and new leaf (shoot)
Dandelion seeds with attached down parachute
Lessons activity is in
What do plants need to grow?
Germination
Seeds
Plant parts
Resource
How a plant grows
Materials
  • Large seeds e.g. broad bean seeds, soaked overnight before use
  • Tiny seeds on parachute e.g. dandelion (pick from dried head for each student)
  • Optional: paper and pencil to draw observations
Procedure

A day or two before the class drop a bean per student into a shallow dish of tap water, so that the coat softens and the seeds swell (and the root will even grow a but). Dry on paper towels before handing to students.

Students pick off the seed coat, and split open their seed. Look for the tiny root sticking out (more visible when the seed is pre-soaked a day longer), and the tiny leaf next to it. (Older students: the root and shoot make up the plant embryo)
The other parts are food for the growing plant, until it has leaves and can make it's own food. (Older students: the cotyledon where the plant gets it's food from as it germinates.)

Time lapse of a bean seed sending out roots and its shoot: https://www.youtube.com/watch?v=w77zPAtVTuI

Give students one dandelion seed (with an intact parachute).
Have them look really closely at the seed hanging from the parachute, and how they get carried in the wind.
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
(Good segue into Wind blown seed design activity.)

Notes

Page 10 from the resource book has a good image of the inside of a seed.

Grades taught
Gr K
Gr 1
Gr 2
Gr 3
Gr 4