activity 15 Growing Underground BROWARD COUNTY ELEMENTARY SCIENCE BENCHMARK PLAN Grade K Quarter 2 Activity 15 SC.F.1.1.2 The student knows how to apply knowledge about life processes to distinguish between living and non-living things. SC.H.1.1.1 The student knows that in order to learn, it is important to observe the same things often and compare them. ACTIVITY ASSESSMENT OPPORTUNITIES The following suggestions are intended to help identify major concepts covered in the activity that may need extra reinforcement. The goal is to provide opportunities to assess student progress without creating the need for a separate, formal assessment session (or activity) for each of the 40 hands-on activities at your grade. 1. Ask, How could you tell if an object was not a seed? (The object did not grow like the plants did.) Ask, What do we call the part of the plant that grows up? What do we call the part of the plant that grows down? (The part that grows up is called the shoot. The part that grows down is called the root.) 2. Use the Activity Sheet(s) to assess student understanding of the major concepts in the activity. In addition to the above assessment suggestions, the questions in bold and tasks that students perform throughout the activity provide opportunities to identify areas that may require additional review before proceeding further with the activity. broward county hands-on science Quarter 2 161
162 activity 15 Growing Underground
activity 15 Growing Underground OBJECTIVES Students learn how seeds grow in the soil by examining sprouted seeds dug up from the class garden. The students guess what the seeds have been doing underground examine seeds dug up from the garden observe how the roots and shoots are developing SCHEDULE About 30 minutes VOCABULARY root shoot sprout MATERIALS For each student 1 Activity Sheet 15 1 magnifier 1 pr gloves, disposable For the class 1 class garden (from Activity 13) 16 cups, plastic, 1-oz 1 fork, plastic 1 marker, felt-tip* 1 overhead projector* 16 paper towels* 1 transparency, Inside a Seed 1 transparency, A Sprouted Seed 16 trays, plastic (flat) 4 water sprinklers water, tap* DSR From Seed to Plant *provided by the teacher PREPARATION 1 2 3 4 5 Arrange to have the use of an overhead projector for this activity. Make a copy of Activity Sheet 15 for each student. Begin this activity when some of the seeds have begun to sprout, about 5 to 7 days after Activity 13. Each of the seeds used for this activity should have a visible root and tiny shoot. Fill the 1-oz cups half full of water. Fill the water sprinklers with water. Each team of two will need a magnifier, a 1-oz cup of water, and (after students have watched you dig up the sprouted seeds) a plastic tray with a sprouted seed and a non-seed object on a numbered paper towel. BACKGROUND INFORMATION The first thing to break open the seed coat and emerge from the sprouting seed is the root, which is usually white. The root will grow downward around obstacles such as rocks and twigs in the soil. broward county hands-on science Quarter 2 163
1 The second thing to emerge from the seed is the shoot, which will become the stem and leaves of the plant. Often it emerges from the seed, pushing upward through the soil, somewhat curled to protect the fragile new leaves. Once the shoot is above the ground, it turns upright; then the leaves open and take on a deeper green color. Students should be able to observe the initial root growth in the seeds that you dig up from the garden, and they will probably be able to see the shoots with their curled-up new leaves. If the sprouted seeds are handled gently, it is possible to replant them and allow them to continue growing. Guiding the Activity Ask, What do you think is happening to the seeds we planted in Activity 13? Tell students that they are going to examine closely some of the objects from the class garden. Have teams come up and watch you dig up the sprouted seeds so that they can see exactly where these young plants come from (see Figure 15-1). Place each seed on a paper towel and write the number of its garden plot on the paper towel. Place a towel with a seed on each of sixteen trays. 164 activity 15 Growing Underground Activity Sheet 15 Growing Underground my sprouted seed Drawings should include seeds with their roots and shoots. Additional Information Some students may suggest that they are growing without knowing exactly what that means. Using a plastic fork, carefully dig up sixteen of the larger seeds from the class garden that have reached the sprouting stage; bean, pea, corn, and sunflower seeds are good choices. Shake each sprout gently to remove most of the soil attached to its roots. Also dig up the non-seed objects, such as vermiculite or gravel, and place one on each tray beside the sprouted seed.
Guiding the Activity Additional Information 1 4 7 10 2 5 8 11 3 6 9 12 2 3 Figure 15-1. Digging up a sprouted seed from the class garden. Distribute to each team of two a plastic tray with a seed and a non-seed on a numbered paper towel, a 1-oz cup half full of water, and a magnifier. Allow students time to observe the objects closely, encouraging them to use their magnifiers for a closer look. Tell students to compare the two objects on each tray. Ask, Have both the items on your tray changed since you planted them in the class garden? Ask, Which of the items on your trays do you think are not seeds? Ask, Why do you think some of the objects have changed? Tell students that you can tell a living thing from a nonliving thing by watching for growth. When living things grow, they change and get bigger. You can tell that seeds are living because they get bigger and sprout. The vermiculite and gravel do not get bigger, nor do they sprout. Thus, you can tell they are not living. If soil is still clinging to the objects from the class garden, have students place them in their small cups of water to rinse them off and then lay them back on the paper towels. No. Students should note that some have changed but some have not. Students should conclude that such items as vermiculite, gravel, and some of the other objects they planted are not seeds because they have not changed and grown since they planted them. Students may say that some of the objects must be seeds because they have changed and are growing new parts. broward county hands-on science Quarter 2 165
4 Guiding the Activity Tell students to focus on the sprouted seeds and look at them closely. Circulate among the teams to help students focus on the seeds and to listen for observations that students make. When all students have had time to observe their seeds, have them place the seeds and trays to one side of their desks and ask, How have the seeds changed? Help students understand that growth includes changes that take place inside and out as well as getting bigger. Tell them that changes took place inside the seed to cause the shoot and root to emerge. Similarly, changes take place inside their bodies when they grow and get bigger. Ask, What are some other things you can look at to decide if something is living or nonliving? Write root and shoot on the board. Explain that the root is the part of the new plant that will grow underground, while the shoot is the part that will grow aboveground. Write the word sprout on the board. Explain that when a seed first grows into a tiny plant with roots and a shoot, we say that the seed sprouted. Project the Sprouted Seed transparency and point out the root and shoot on the corn seed (see Figure 15-2). Challenge students to look for the roots and shoots on their seeds. 166 activity 15 Growing Underground Additional Information Remind students to handle the seeds gently to avoid breaking them apart. The seeds have started to grow new parts. Elicit from students the idea that living things make more living things like themselves. The corn plant makes seeds that, in turn, make more corn plants. shoot Figure 15-2. A sprouted corn seed. root seed Tell students that the roots, which usually grow first, are often white and may have small hairs on them, while the shoots may have folded leaves and a pale green color. Some seeds develop their shoots much earlier than others.
5 Guiding the Activity Project the Inside a Seed transparency and ask, Which part of the seed grows into the new plant? Ask, Can you find the seed coat of your seed? Additional Information the roots and shoots The seed coat may still be around the seed like a loose skin, or it may have fallen off in the soil. You may want to help students search in the soil for missing seed coats. 6 7 Ask, How has the seed food part of your seed changed? Distribute a copy of Activity Sheet 15. Have students draw their seeds with their roots and shoots. As appropriate, read or review pages 4 6 from the Delta Science Reader From Seed to Plant. As students complete their drawings, ask for volunteers to help you replant the seeds in the class garden. Have students replant each seed in the plot that has the same number as the paper towel. R EINFORCEMENT When the seed first sprouts, the two parts of the seed swell with water and enlarge. After the seed has been growing for a while, the parts may shrink as the stored food is used up. Encourage them to make their drawings larger than the actual sprouted seed and to show all its parts. Tell students that if the seeds are handled gently they will continue to grow. To replant a seed, place the seed back in the hole, root down, and gently sprinkle soil over it. Water it with the water sprinkler. Give students plastic forks and allow them to gently dig up one of the seeds they each planted in a planter cup to see how it has changed. Ask them to compare the development of their seeds with the seeds from the class garden. Tell them to replant the seeds carefully when they have finished. Assessment Opportunity This Reinforcement also may be used as an ongoing assessment of students understanding of science concepts and skills. SCIENCE JOURNALS Have students place their completed activity sheets in their science journals. C LEANUP Either discard the non-seed items or, if you wish, wash, dry, and return them to the kit. Rinse and air-dry the trays, plastic fork, and 1-oz cups before returning them to the kit. Place the transparencies and the magnifiers in the kit. Return the water sprinklers to their place in the classroom. broward county hands-on science Quarter 2 167
Connections Science Challenge Explain that not all plants grow from seeds. Some grow from a parent plant s roots, stems, or leaves. For example, new potato plants grow from the eyes on a potato. (Potatoes are not roots but swollen sections of underground stems called tubers.) New plants also can be grown from root vegetables such as carrots, beets, onions, parsnips, and turnips. Other plants, such as strawberries and spider plants, put out special stems that produce new plants. Stem or leaf cuttings from some plants will develop into new plants. Demonstrate these propagation methods for the class, as described in this connection. When the new plants are well established, help students transplant them to small pots and take them home. Growth from eyes: Leave a potato out in the light so students can see new plants sprout from its eyes. When the shoots are a few centimeters long, plant the potato in a pail filled with potting soil. At the end of the year, let students dig up the plant and look for small, new potatoes developing. Growth from roots: Cut the top off a carrot, beet, turnip, or other root vegetable, and trim off all but about 3 cm (1.2 in.) of the old stem and leaves. Plant the root-top in a shallow dish of sandy soil. The old root-top will grow new stems and leaves. Growth from runners: Plant a strawberry plant in the center of a wide box so it will have room to spread. Hang a spider plant in a well-lighted window. Have students check both plants regularly to see if runners and new plants develop. Growth from stems: Cut trailing stems from plants such as ivy, philodendron, and pothos, and place them (cut end down) in jars filled with water. Add fresh water as needed. Students will be able to see new roots growing at the cut end. When the roots are well developed, plant each cutting in soil. 168 activity 15 Growing Underground Growth from leaves: African violets and some other fleshy-leaved plants will grow new plants from a leaf cutting. Leave about 3 cm (1.2 in.) of stem on the leaf, and plant it at a 45-degree angle in fine soil. New plants will grow at the leaf s base. Science Extension The following activity will allow students to observe root growth continually as a seed sprouts. Set up the jar yourself or have each student team do so, as follows: Fold and roll up several paper towels and put them into a clear plastic jar. Slip a large bean seed between the towels and the side of the jar, about one third of the way down from the top. Add water to the jar so the towels are moist but not sopping wet. Have students examine the seed at least once a day for a week or more, adding water as needed to keep the towels moist. Students will see the seed begin to swell, then a tiny root push out of the seed and grow downward (as a sprout grows upward), and then smaller roots grow from the main root. Students might like to try this with other types of seeds, including those used in the class garden and the planter cups. Science and Social Studies Suggest that the next time students go to a grocery store, they look at the fruits and vegetables on display in the produce department and try to decide which part of a plant each one is. For example, asparagus and celery are stems. Foods like tomatoes, cucumbers, peas, beans, and squash, for example, are the parts of a plant that contain seeds. Carrots, beets, onions, and radishes are roots. Spinach, collard greens, chicory, kale, and heads of lettuce and cabbage are leaves. In a follow-up class discussion, let students describe what they found.