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Let's Start Growing

Keywords: endosperm, embryo, seed coat, dormant, renewable resource, germinate; Lesson Plan Grade Level: third grade; Total Time Required for Lesson: 60 minutes; Setting: classroom

Goals for Lesson

  • Students will understand the growing requirements of a tree.

  • Students will begin to grow a tree from seed.

Materials Needed

  • tree seeds (acorns, maple, etc.)

  • potting soil

  • empty 2 liter soda bottles (one for each student)

  • science journals

  • pencils

  • rulers

  • masking tape

  • markers

  • paper cup

  • large butter dishes (one for each student)

State Standard: (4.2) E & E Standards: Renewable & Nonrenewable Resources; (4.3) Environmental Health, Ecosystems and Their Interactions

Subjects Covered: earth science, geography, math

Topic Covered: the life of a tree

Teaching Model: Hands-on

Methods

Making connections: An understanding of how seeds become plants will be reviewed from prior lesson. Introduce the beginning of a tree and explain that trees do not need people to plant them and that they are a renewable resource. Write vocabulary words on the board and review each one. Ask students if they know the definition. If they answer correctly, write it on the board; if not, give the definition and write it on board. Leave on the board because you will be using them later in their science journals.

Background: Inform students of the following:

  • A tree seed contains an embryo (baby) tree. This embryo already has tiny leaves, a stem, and a point that will become a root. The embryo is surrounded by endosperm--the food supply for the developing tree.

  • Once the seed falls from the tree to the ground, it is covered by leaves and soil. When the ground is warm enough and other conditions are just right, the seed begins to grow, using the endosperm for food. Because the seed is able to grow without the help of people, it is a renewable resource.

  • Eventually, the endosperm is consumed. The seed then must seek other sources of nutrients by sending out a root. The seed anchors itself to the ground and draws water and nutrients from the soil.

  • Finally, the tiny tree emerges from the ground and the leaves appear. The leaves enable the growing tree to produce its own food. The shell, or seed coat, of the embryo tree then falls off. Some seeds, such as acorns, have tough, protective coats. Other seeds, such as maple, have light coverings.

  • Show the students the different seeds as you are explaining the coverings.

  • Tell them that seeds are scattered in many different ways. Animals eat seed-bearing fruits and deposit the seeds on the soil in their waste.

  • Wind carries winged and others light seeds.

  • Sticky seeds often cling to animal's fur or your sweater and ride along to new locations.

  • Lakes and streams give some seeds a boat ride to new areas.

  • And, of course, gravity pulls seeds from the trees, giving them a long ride downhill to a new home.

  • The maple drops seeds onto the soil in early summer. These seeds are already mature. They start to germinate shortly after hitting the ground.

  • The nut-bearing trees drop their seeds in the fall.

  • These seeds are dormant and will not germinate until the spring.

  • Dormant seeds must go through a cold spell before they germinate. In nature, winter provides these cold treatments.

  • For what we will be doing with this lesson we will be using seeds with light coverings.

Review of prior learning: Review with class the vocabulary from board and have them write vocabulary in their journals.

Learning Activity

  • Pass out 2 liter bottles to each student.

  • Have the students poke four or five holes in the bottom of their bottles.

  • Give each student a large butter bowl.

  • Give each student a strip of tape and a marker.

  • Have students put tape around the bottom of their bottles and write their names.

  • Have students take turns coming to the front of the room and filling their bottle ¾ full with the potting soil.

  • After all students have done this, pass out two seeds per student.

  • Have students plant their seed about ½ way down into the soil.

  • Have students water the seeds through the bottom of the bottle by placing the bottle into the butter bowl and filling it up with water.

  • Sit the bottles on the windowsill for light.

  • Have each student record the date, time, and type of seed planted in their journals.

  • Inform students that they must keep their plants moist and in the sunlight and that the dates and amount of water are to be recorded in their journals every time they water.

  • After the trees emerge from the ground, students are to record the size of their new tree in their journals.

  • After trees are sturdy enough to be replanted they can be taken home and planted outdoors. So, you will want to plan this activity to correspond with the climate in your area.

Wrapping up the Lesson

Remind students that some seeds must be softened or go through a cold spell before they will germinate, so this experiment will not work with all seeds.

Assessment

Check the students' journals for the correct dates, amounts, and measurements throughout the experiment.

Reference

Hansen, Robert S. (1996). Trees + Me = Forestry. University Park, Pa.: The Pennsylvania State University.

Author

Kimberly McDowell, second grade teacher, Bald Eagle