Download Inside a Seed Lesson Plan

Inside a Seed Lesson Plan
Learning Objectives: Students will:
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Learn how plants produce seeds
Observe what is inside a seed; identifying the embryo, endosperm, and seed coat.
Identify the difference between monocots and dicots
Idaho State Standards Met: K.S.3.1.1, 1.S.3.2.1, 2.S.3.2.2, 3.S.3.1.1, 4.S.3.1.1, 5.S.3.3.2,
6.S.3.3.3, 7.S.3.1.1, 9-10.B.3.1.2
Materials: For each student or team of students:
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Bean and corn seeds (soaked overnight)
A magnifying glass
Toothpicks
Scissors
Paper plates
Background: All seeds have three parts: a seed coat which protects the inside of the seed,
food for the plant to grow (endosperm), and a baby plant (embryo). The seed usually begins to
develop when the embryo is exposed to water. The water swells the embryo and bursts the seed
coat. During the earliest phase of growth, when the embryo has no leaves and can’t perform
photosynthesis, the endosperm serves as a food source.
There are two groups of flowering plants. Monocots have one seed leaf, or cotyledon (grass,
cattail, lily), dicots have two in each seed (peanut, sunflowers, trees).
Focus Phase:
Ask students: Why do plants produce seeds? (To reproduce their species) How are seeds
produced? (Via the process of pollination. Explain that pollination is the process of moving pollen
from one plant to another. It is through this process that plant reproduction happens.)
Give student’s pre-cut fruits and vegetables. Ask students to remove the seeds of the fruits and
vegetables. Use Popsicle sticks to help remove and gather seeds. Tape the seeds to
construction paper labeling the seeds by name. Discuss different sizes, and forms of seeds from
fruits and vegetables.
Activity:
1. You will need bean seeds and corn seeds (soaked overnight), a magnifying glass, a
toothpick, scissors, and a paper plate for this experiment.
2. Find the largest bean seed you can. Peel off the seed coat VERY carefully with your
toothpick. It will be wrinkly after soaking all night. Thie seed coat protects the plants and
keeps it from drying out.
3. You are looking at the endosperm. It is packed around the embryo in the form of special
leaves called cotyledons or seed leaves.
4. Now open the seed VERY carefully along its natural seam.
5. The seed will divide into two parts. Each part is a cotyledon or seed leaf. Bean seeds
are dicots because they have two cotyledon.
6. Get a magnifying glass and look closely at the embryo. You can see the root, the stem,
and the leaves of the embryo. It really is a very tiny plant!
7. Now place a corn seed on your paper plate and remove the seed coat. The seed coat on
corn is a little stronger than the seed coat on lima beans.
8. After you take off the seed coat, try to split the seed into two parts. Hint: It won’t split!!
Corn seeds are monocots. They only have one cotyledon. Use scissors to cut in half
lengthwise.
9. Now you can see the embryo. Look at it with the magnifying glass, and see if it looks like
the embryo of lima beans.
Follow up: After the activity, hold a discussion about the purpose of each of the three parts of a
seed.
Extensions: Students separate the seed cotyledons, leaving the plant embryo on only one
cotyledon. Students will observe the embryo grow into a plant and will conclude that the
cotyledon by itself does not contain right material to produce a new plant.