Author: DeRoo, Sally A.
Grade level: K-8
Objectives/Understandings: Some seeds store more food in them than others. Seeds swell when they take in water. Nourishment for the germinating seed is stored in the seed leaves.
Resources/Materials: Large plastic jar with a wide mouth, cardboard, foil, scissors, heavy cotton, pumpkin and cucumber seeds.
- Cut a piece of cardboard larger than the mouth of the jar. Measure both and cut the cardboard one-half inch greater in circumference.
- Cover the cardboard with foil.
- Poke a hole in the center of the round disk. Fit the disk over the mouth of the jar.
- Swirl the cotton into a heavy cotton rope about 18 inches long.
- Pull the end of the cotton very carefully through the hole in the cardboard. It should reach the bottom of the jar.
- Arrange the remaining cotton rope neatly on the top of the disk.
- Fill the jar one-quarter full of water.
- Carefully place several pumpkin and cucumber seeds on the cotton.
- Sprinkle the cotton with water.
- Place the cotton "seed bed" in a window where it does not receive direct sunlight.
In several days (if kept moist), the seeds will germinate. They swell as they take in water. The seeds sprout, producing very fleshy cotyledons. As the nourishment in the leaves is used, they will shrink and drop off. If the plant does not receive additional food, it too will die.
Pumpkins and cucumber seeds are dicotyledons or two-part seeds.
Follow-up Activities (Optional)
In measuring the mouth of the jar and the cardboard, students measure for circumference and diameter. Several different size jars could produce a group project. Measure the diameter in centimeters. Measure liquid when filling the jar. How much is one-quarter full?
240 cc = 240 gm - 8 oz = 1 cup (approximately correct for measuring water).
This "measuring formula" is especially fun for later elementary children. Why not make it the "Math Stumper" of the day?
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