Seed Dispersal

Tags: Seeds, Dispersal, Class Ideas, Indoors, Outdoors, All-Seasons, Spring, Anytime, 2nd-5th grade

Seed Dispersal

Time : 45 mins 

Outline

Greeting and Review	Start in the same space if possible for every class (ex: The Circle, Pond, Back benches) Have the class look around at all the vegetation and ask them how did they start? (as seeds) How did the seeds get there? Introduce/review the word disperse – to scatter, to spread out
Main Lesson	Students will discover/review the concept of how seeds travel (disperse). Students will predict ways in which seeds are dispersed. Students will taste different seeds.
Activity 1	Observe seeds and record Materials Needed: Pictures of seed dispersion (see link below) Examples of seeds from each of the 5 dispersal methods (wind, gravity/rolling, water, animal, explosion)- 4 or 5 of each (ex: dandelion, acorn, coconut, berry or fruit, seed pod)  Balloons Flour Something sharp to pop a balloon, like a pin Plate/container to hold the seeds Record sheet
Activity 2	Seed tasting Materials Needed: Variety of edible seeds, for example: Strawberries, Grapes, Sunflower seeds, Bananas, Kiwi Plates or napkins to hold the seeds
Cleanup	Children – (Allow 5-8 mins for any cleanup)  Adults – (Allow 10mins for cleanup)
Goodbye	2-3 minutes to say goodbye
External References	None
Worksheets/Pictures	Observation sheet – seed dispersal

It is a good idea to split the class into smaller groups and rotate activities.  To grab the attention of students, you can say “GIVE ME 5” which is widely used at Becker Elementary or employ other techniques Click here for Teaching and Behavior Management.

ACTIVITY 1: Observe seeds and record

1. Before the children arrive, set up 4 or 5 tables with the containers of seeds from each dispersal method at each table. And fill a balloon with 1 tablespoon of flour (bird seeds work great too), blow air into it and tie a knot (keep with you)
2. When kids are in their seats, review the different methods of seed dispersal – have students volunteer answers.  As they do, show the picture of that method, for example, student says animal and you show picture of bird and sweater(representing fur), wind=dandelion; water=coconut; gravity =apple, or coconut.  The balloon with flour represents explosion, demonstrate this by popping the balloon and watching the flour disperse.
3. Next have the students observe the seeds on the plate and record their observations. 
4. Share and compare observations. 

Encourage students to raise their hand and ask questions if they are unsure about something.

 

ACTIVITY 2 : Seed tasting 

1. Divide the seeds so each child tastes them all.
2. At their tables, have students discuss and share which method they think that seed would have been dispersed.

 

ADDITIONAL ACTIVITIES (Include additional activities)

1. Walk around the garden and find different examples of seeds

CLEANUP & GOODBYE (Include Cleanup and Goodbye)

• Set a timer (on your phone or on a watch the clock) 10 minutes or so before the end of class to gather the class and organize the space. 
• Allot 5-8 mins for any cleanup – put away supplies, tools, clean dishes, wipe down tables etc.
• Allot 2-3 minutes to say goodbye. Try ending class in the same space each class,  if you can. Depart with an informal goodbye of your choice, a song, a poem, a high five as they walk out the door, etc.

Worksheet Links

Background Information

Most of the plants we’re familiar with start out as seeds in the ground. Sometimes people plant the seeds, like a farmer sowing crops or someone growing a vegetable garden or flower garden in their backyard, but how do seeds get planted in nature? There are whole forests of trees all around the world that nobody planted. Even the grass in an open field came from seeds. And Texas wildflowers really are wild – nobody planted them, so how did the seeds end up there?

Sometimes seeds simply fall from the parent plant and grow where they’ve fallen, but far more often the seeds get moved somewhere away from the parent. We call this movement of seeds away from the parent seed dispersal. (“Dispersal” means spreading out over a wide area.) There are three main types of seed dispersal: animal, wind, and water.

Seeds can be dispersed by animals in a variety of ways. Many plants develop their seeds inside a fruit of some kind. When the animal eats the fruit, it also eats the seeds. But each seed has a protective shell called the seed coat that protects the seed from being digested. The seed passes through the animal’s digestive system unharmed and ends up coming out the back end when the animal poops. Since animal poop makes good fertilizer for plants, the seed has been moved to another place and then deposited with fertilizer to help it grow. Other seeds, like the sticker burrs common in Texas, have tiny spikes or hooks on them. These catch on the feathers and fur of animals (and on socks and pant legs and shoelaces of people) and are carried away from the parent plant before falling off. Seeds can also be dispersed by animals such as squirrels, who bury so many acorns that they never find them all.

Some seeds are specifically designed to be carried on the wind. You may have played with a dandelion that has gone to seed. The gray-white fluffy “parachutes” can be easily blown right off the plant and carried away by the wind. Eventually the seeds land somewhere and start a new dandelion plant. Maple seeds are another type of seed that is easily carried on the wind. Their one “propeller wing” helps keep them in the air longer when they fall from the tree, giving the wind more time to carry them away.

Plants that grow near water often rely on moving water to disperse their seeds. Coconuts are one example – coconuts float in water, so a coconut that has fallen from the tree and rolled into the water might be carried some distance before washing up on land again and taking root.

The seeds of different plants are specifically designed for dispersal by one means or another. Seeds inside fruit and seeds with tiny hooks are specifically adapted to being dispersed by animals. Lightweight seeds with parachutes, sails, or propeller blades are specifically adapted for dispersal by wind. And thick-shelled seeds that float are perfect for dispersal by moving water. You can often tell something about how a plant’s seeds are usually dispersed in nature simply by looking at the seed itself.

In each case, the seed is deposited in a new site, ready to germinate and grow into a new plant as soon as the conditions are right. Normally the conditions required before a seed begins to grow are a warm, moist environment. Since seeds are often deposited in autumn when the air and ground are cooling off, the seeds usually remain dormant through the winter and begin to sprout in spring when warmer temperatures and spring rains provide the right conditions for growth.

Seed dispersal is important for a plant species’ survival. Without seed dispersal, the seeds from a tall tree, for example, would fall in the shade of the parent tree and wouldn’t get enough sunlight to become tall trees themselves. Dispersal also helps spread out a plant species over a wider area. If a plant species is limited to a small area, then a single hard freeze or a root disease could kill off the entire species. By spreading its seeds over a wider area, a plant species has a greater chance of maintaining long-term survival.