Activity

Seed hunt and classification

Summary
Look for seeds in a garden (or use a collection indoors). Group them by dispersal mechanism: wind, animals, self dispersal, water (if available), or show how they are part of the life cycle of plants.
Science content
Biology: Features, Adaptations of Living Things (K, 1, 3, 7)
Biology: Life Cycles (2)
Materials
  • either: garden or school grounds with many plants and a Fall day when seeds have started forming
  • and/or: a seed collection, optionally including different dispersal types e.g. maple and dandelion for wind, berries and seeds with burs for animal, poppy or fireweed for self dispersal
  • optional: worksheet or map for students to show where they find the seeds, and what they look like
    Procedure

    If outdoors: hunt for seeds, or places that seeds will be.
    Students may need examples of seeds to find, or show students dead flowers and the base of the flower where the seeds will be forming. Point out other seeds hanging from trees and in grass heads if students are not sure where to find seeds. Tell them that seeds are inside berries.

    Optional: ask them to draw a sketch of each kind of seed they find on a map of the garden they are in.

    If indoors: give students a seed collection to look at and draw.

    Classifying seed dispersal mechanisms
    With discussion of what the students found and noticed, add each of their drawings to a board, placing each seed in a quadrant of a board divided by dispersal mechanism (wind, animal, self dispersal) - but with no labels (yet).
    Once all the seeds that students found are added to the board, discuss why they are grouped in this way - according to the how the various structures attached to the seed help the seeds spread away from the parent plant (called the "dispersal mechanism"). Starting with the wind blown seeds is the most accessible for students to understand the concept of dispersal mechanism, with the familiar maple seed helicopter.

    Examples:
    Wind dispersal: light structures with a large surface area make the seeds float slowly down to the ground, and are blown sideways by the wind to land away from the parent plant e.g. the feathery parachutes of dandelion, the helicopter wings of maple.
    Animal dispersal: berries (that get eaten and pooped out far away), barbed seeds (that get caught on animals' fur).
    Self dispersal: pods that explode open (e.g. fireweed) or "pepper pots" that sprinkle seeds away (e.g. poppy).
    Optional: Water dispersed seeds e.g. coconut can be added to the last quadrant of the board.

    Try these webpages for images of seed dispersal mechanisms:
    https://amoobabatundeyakub.blogspot.ca/2014/06/dispersal-of-fruit-and-s…
    http://maggiesscienceconnection.weebly.com/uploads/5/1/0/5/5105330/2467…

    Seeds in the plant life cycle
    Place seeds on a board, then while asking students what they know already about the cycle, place a small plant, then a flower, on the board. Draw arrows to connect the plant parts into a life cycle.

    Grades taught
    Gr 1
    Gr 2
    Gr 3
    Gr 4
    Gr 5