A lesson plan for 2nd and 3rd graders, developed by the Michigan Farm Bureau

Objectives:

• The students will understand the importance of seeds and the plant cycle.
• Students will learn the types and parts of seeds and their different uses.
• Students will develop an understanding of what seeds need to grow.

Materials:

• Seed samples, each containing 5 or more different kinds of seeds (seed corn, wheat, soybeans, maple seeds, dry beans, cherry pits, apricot pits, sugar beet seeds, etc.)
• Seed observation handouts
• Seed parts handouts
• Seed growth sequencing handouts
• Sample products that are made from seeds (bread, cereals, milk, juice, fruits, vegetables, etc.)
• Soil sample bags
• Lemon juice (to make water acidic)
• Two plastic milk jugs (one labeled "1" and filled with plain tap water; the other labeled "2" and filled with tap water and lemon juice)
• Plastic cups for pH testing (2 cups per group)
• Litmus paper for testing pH
• 20 data sheets

Part I - Types of Seeds

During Part I, students will use their observation skills to identify how seeds are different and how they are alike.

1. Divide students into groups of 4-5 students each.
2. Distribute 5 to 6 different seeds and an observation sheet to each group. (Click here for a printable observation sheet.) Instruct the students to use all their senses to observe the seeds, and to record their observations about how the seeds are different on their sheet.
3. Have each group share one way that the seeds are different from each other, and list on the board (size, shape, color, texture, etc.).
4. Have the students list ways the seeds are alike, and list these on the board (all grow into plants, all need water, soil and sun, all came from plants, etc.)

Part 2 - Parts of Seeds

Every seed, no matter how big or small, has the same three parts: the embryo, which will grow into the new plant; the food supply, that will help the embryo grow until it can see the sun; and a seed coat, to protect the embryo and the food supply.

1. Distribute the "Name the Parts of a Seed" handout, and help the students correctly label the seed parts on their diagram. (Click here for a printable handout.)

Part 3 - Plant Cycle

If all seeds have the same three parts does that mean they will all grow into the same plant? No, of course not.  Each seed will become a different plant when it grows. But, every seed goes through certain stages when it grows and these stages combined are called the plant cycle. 

1. Show the students a soybean seed, and discuss the seeds plant cycle.  If the soybean seed was planted and given the water and nutrients it needed, pretty soon it would come up out of the ground as a soybean seedling, or small plant. With sunlight and nutrients, the seedling would grow to become a mature plant. Once the plant is mature (all grown up) it will produce more seeds, which starts the cycle all over again.
2. Distribute the "How Do Seeds Grow?" worksheet, and have the students number the stages of the plant cycle in the correct order. (Answer: 3-4-1-2) (Click here for a printable worksheet.)

Part 4 - Uses of Seeds/Plants

Once students understand how seeds are alike and different, and how they grow, it's time to discuss why seeds are important.

1. Ask the students if any of them had seeds for breakfast.  From the sample food products, show the students which ones were made from products that started as seeds (examples: bread/toast, bagels, Cheerios, Frosted Flakes, Rice Chex, Rice Krispies, pieces of fruit, etc.).
2. Discuss how most foods we eat start as seeds that grow into plants that are then processed into the ingredients for the foods we eat.  For instance, corn seeds grow into corn plants.  The corn is harvested and processed into corn meal, which can be used to make corn flakes or corn muffin mix.  Even milk can be traced back to a seed.  Milk comes from a cow.  Cows need food to produce milk.  The hay and grain they eat come from seeds.

Part 5 - Needs of Plants

It takes a lot of seeds to make all the foods we eat, and to make the food we feed to livestock, so farmers have to know what each type of seed needs to grow.

1. Ask students what they think seeds need to grow, and list their correct answers on the board (List water, nutrients/food, soil and sunlight).
2. Discuss how these things are important to know, but farmers need to know even more than that to grow seeds. They need to know if their soil has enough nutrients in it to help the seed grow. To find out if the seeds can grow in the soil available, farmers collect soil samples from their fields and have them tested at a laboratory. Sometimes, a farmer will do his or her own soil test - a pH test.
3. Explain to the students what a pH test is.  Testing a soil's pH level means measuring how acidic the soil or water is. Most seeds like soil and water with very little acid.
4. Give each student two plastic cups, two pieces of litmus paper, and a lab sheet for recording results.  Have the students label the cups, "1" and "2". (Click here for a printable lab sheet.) Pour a small amount of water from plastic jug "1" into cup "1", and from jug "2" into cup "2".
5. Have the students dip the litmus paper in each glass to see what happens. Litmus paper will turn color if there is acid in the water and it will stay the same if there is not.  Observe what happens when the litmus paper is dipped in the two cups.  Which contains acidic water, "1" or "2"?  If a farmer found that his soil or water had more acid than it should, he or she would have to add limestone or other material to the soil reduce its acidity. That is why farmers use fertilizers - to provide the nutrition that seeds need to grow.

This lesson plan can be followed up with a seed planting exercise.