Grade 5 Science
Core Unit: Plant Structure and Function

Unit overview:

This unit focuses on the functions of the leaves, stems, roots, and flowers of plants. In addition, the identification of plant species is emphasized. Saskatchewan field and forage crops are used to show plant diversity. The importance of agriculture is discussed.

Related units:

The grade 1 Core Unit, Plants, involves the identification of plant parts. Conditions producing optimal growth are described in the grade 2 Core Unit Plant Growth. The optional Units in grade 3 Plant Structures and Adaptations, in grade 4 Plant Diversity discusses plant diversity and adaptations. Work cooperatively with the grade 2 teacher to plan field trips together, or to team-teach portions of the unit. Try to get older students working cooperatively with younger ones.

Suggested themes:

adaptations, conservation, farming, foods, homes, plants, renewable resources, reproduction, soil

Factors of scientific literacy which should be emphasized:

Common Essential Learnings foundational objectives which should be emphasized:

To use a wide range of possibilities for developing students' knowledge of plants. (COM)
To support the development of a positive disposition to life-long learning. (IL)
To develop an understanding of how knowledge is created, evaluated, refined, and changed within science. (CCT)

Science foundational and learning objectives:

Describe the characteristics of vascular plants.
1. Identify the roots, stems, leaves and flowers of plants.
2. Observe and describe fibrous root systems and tap root systems.
3. Use leaves and seeds to identify plant species.
Explain some of the functions of the roots, stems, leaves, and flowers of plants.
1. Observe and describe the movement of water through a stem of a vascular plant.
2. Compare and contrast the processes of photosynthesis and respiration.
3. Describe the process of pollination and seed production.
4. Observe and describe plant adaptations.
5. Experiment with the variables which influence seed germination.
Describe agriculture in Saskatchewan as it relates to field and forage crops.
1. Identify some field crops and their products.
2. Recognize the importance of plants in the prevention of soil erosion.

Suggested Activities:

Set up a plant so that one of its leaves is inserted into a test tube. Support the test tube and seal the mouth of the test tube with nonabsorbent cotton. Care for the plant normally and observe the inside of the test tube.
Factors: B1, B4, C2, C3, C6, C8, C9, C12, F5, G3
Objectives: 2.2
Assessment Techniques: 1, 3, 5, 8
Common Essential Learnings: Critical and Creative Thinking. The students must make inferences and form hypotheses from the observations which they make. Is it water which forms in the test tube? Where does it come from?
Allow a hardy classroom plant, such as a coleus, to wilt by not watering it, or by placing it in very bright sunlight. What happens to the leaves? Where are the leaf openings (stomata) situated on a wilted leaf? Why might this occur? Add water and observe.
Factors: B1, C3, C6, C8, C12, E2, F1
Objectives: 2.1, 2.2
Assessment Techniques: 1, 3, 5, 8

Common Essential Learnings: Critical and Creative Thinking. This is a good activity to discuss the difference between cause and effect, and correlation. Procedures and results of experiments need to be analyzed to determine if there is a cause and effect relationship. This involves identification and analysis of the variables involved.
Supply each group with several long-stemmed dandelions. Have the students slice each stem into three strips running the length of the stem. Wrap a small piece of aluminum foil around the end of each strip. Place two of the strips so that their ends are in a container of water and the third strip is not. Observe what happens to each segment of the stem.
Factors: B4, C2, C6, C9, C10, F5
Objectives: 2.1
Assessment Techniques: 1, 3, 5, 8
Common Essential Learnings: Critical and Creative Thinking. This activity shows a clear cause and effect relationship.
Cover the drainage holes of an unglazed clay flower pot with adhesive tape so that the pot will hold water. Stand it in the corner of a large flat container and put a 3 cm to 4 cm layer of soil in the rest of the flat. Plant some beans (lima beans grow quickly) in the soil at various distances from the pot in the corner of the flat. Fill the pot with water, and keep it full, but don't water the rest of the flat. Water will seep out of the pot into the soil. Keep a daily record of the growth of the beans. After two weeks, dig up a sample of the bean plants so that each group has one. Examine their root systems and record the data on a master chart representing the flat in which the plants are being grown. Repeat this examination after three and four weeks.
Factors: B1, C2, C6, C12, E2, F1, G3
Objectives: 1.2
Assessment Techniques: 1, 3, 4, 5, 8, 9
Common Essential Learnings: Critical and Creative Thinking. This illustrates the role of experimentation in understanding plant growth. It gives students the opportunity to relate their findings to the functions of roots.
Get one fresh carrot for each group of students in the class. Cut off the tops of the carrots and distribute them to the groups. Ask each group to remove the top centimetre of the core of the carrot. Put some white sugar in the cavity and place the carrot upright in a jar containing enough coloured water to come about one-third of the way up the carrot. Observe the carrot the next day.
Students must ask relevant questions, and structure their inquiries, in their attempt to interpret the observations they make.
Factors: B1, B4, C6, C8, C12, F1
Objectives: 1.2
Assessment Techniques: 1, 3, 5, 8
Sprout some bean seeds and alfalfa seeds. An easy way to plant the seeds so that they can be monitored at all times during their development is to use paper towels in a baby food jar. Fold one towel so that it is the same height as the jar. Form the folded towel into a cylinder and place it in the jar so that it lines the inside surface of the jar. Crumple a second towel and place in the centre of the jar. This towel will hold the folded one against the walls of the jar. Fill the jar with water and let it soak the towels. Pour off any excess water. Plant the seeds by placing them about halfway to the bottom of the jar between the inner surface of the jar and the outside of the folded paper towel. Keep the towels moist.
Provide each student with a jar, or four or five jars per group. This will provide plenty of data for analysis.
When the seeds have sprouted so that the root is 2 cm to 4 cm long, use hand lenses to examine the roots for root hairs and for secondary roots. How can the two types of structures be distinguished? Have the students discuss their observations and propose ways to answer the questions they generate.

Factors: B1, B4, C2, C6, C11, C12, F1
Objectives: 1.1, 1.2
Assessment Techniques: 1, 3, 5, 8
Take the students for a hike in an area where there is a variety of plants. Observe the diversity of stem types. Take samples which illustrate some of these stem types. Stress that plants should not be collected indiscriminately. Care should be taken to restrict collecting to the species which are very common, and taken only from places where collecting is acceptable. Before any collecting is done, it would be good to research local species which are endangered or protected.
Factors: A2, B4, C6, C8, C12, E2, F4, F5, G3
Objectives: 2.4
Assessment Techniques: 1, 2, 3, 4, 5, 9
Common Essential Learnings: Personal and Social Values and Skills. By familiarization with the intricacies of the environment, and encouragement to observe and care for it, students will begin to value and respect the environment.
A visit to a greenhouse or a field trip in the spring will allow students to bring back detailed descriptions, sketches, or photographs of a variety of flowers. A good project is to locate wild flowers as soon as they come out in the spring and continue to observe and describe them every week until they produce seeds. Prepare a spring calendar, showing the dates when different wildflowers first emerge.
Factors: B1, B4, C2, C6, E2, F1, F4, G3
Objectives: 2.3, 2.4
Assessment Techniques: 1, 3, 4, 5, 9
Common Essential Learnings: Independent Learning. This task is a long term one, which requires commitment and persistence. Students should also be involved in planning activities such as this.
Encourage the students to bring grains and seeds from as many different plant species as possible. Wheat, oats, barley, sweet corn, popcorn, raw peanuts or sunflower seeds, canola, garbanzo beans, grapefruit seeds, and dandelion seeds are just a few.
For each type of seed, produce a poster which shows: the name of the plant; a sample of the seed(s); a sketch of the plant; a sketch and description of the structure in which the seed is found. Some of the seeds could be planted and the development of the plants described on the poster.
Refer to activity 6 for a description of how to plant the seeds.
Factors: B1, B4, C2, C6, F1, F4
Objectives: 1.3, 2.5
Assessment Techniques: 1, 3, 5, 9
Common Essential Learnings: Independent Learning. Students have had experience with grains and seeds and yet may never have associated them with the production of new plants. Encourage them to look at what is around them from a different perspective. What things have escaped their notice because they are so common?
Ask students to brainstorm all the pairs of variables which might be tested to study the germination of seeds. Examples are: light/dark; cool/warm; wet/dry; pre-soaked/dry; seeds placed sideways/erect.
Devise a procedure to test the germination of seeds, using one of the pairs and keeping the other variables constant. In grade 5, it is best to test one variable at a time. To test for the difference between cool and warm, ten peas might be soaked overnight and five placed in each of two baby food jars as described in activity 6. The jars would be covered with foil to exclude light, and unwrapped once a day for inspection of the seeds, and the addition of water to keep the moisture level constant. One jar would then be placed in a cool location, and one where it is warm. Care should be taken to ensure that the temperatures in the locations chosen remain fairly constant during the course of the experiment.
Have students experiment with a variety of seeds best suited for their location. Prior to beginning this activity, students could gather various varieties of grains or seeds produced in Saskatchewan. Record germination and maturity dates. Correlate this information with the number of frost- free days in your location, to determine those plants most suited to that growing area. Students could check with farmers or extension agrologists to verify their findings.
Factors: B1, C6, C8, C9, C11, C12, F1, F5
Objectives: 2.5, 3.1
Assessment Techniques: 1, 2, 3, 4, 5, 8

Common Essential Learnings: Critical and Creative Thinking, Independent Learning. The students focus on gaps in their knowledge, and on ways to discover and substantiate knowledge. The use of resource materials allows students to perform a variety of research projects independently.
Experiment with hydroponic growth of plants. The jar system described in activity 6 could be used, or a more elaborate system constructed or purchased. Using the jar system from activity 6, a nutrient solution instead of water would be added to keep the towels moist. The effect of various nutrient solutions on the same species of plant could be studied.
A competition could be created where the students are awarded prizes for the largest plant, the greatest number of flowers, or other categories which the class could decide upon before the investigation begins.
The activity could also be related to the Core Unit on Resources. Students could attempt to determine if hydroponics can replace soil for plant growth. Could enough food be grown if only hydroponics were used? How does the cost of hydroponics compare with other methods?
Factors: B1, B4, C2, C6, C8, C12, F1, F5, G3
Objectives: 1.1, 1.2, 3.2
Assessment Techniques: 1, 3, 4, 5, 8
Common Essential Learnings: Critical and Creative Thinking. Students can compare the growth of plants by hydroponics and the growth in soil, explaining the similarities and differences.
This activity is used to study the relationship between the number of days of growth and the number of secondary roots produced from the primary root. Soak navy beans, or another variety, for 24 hours and then place them in baby food jars as described in activity 6. Plant them close to the top of the jar, so that there is maximum length for root growth. Draw a chart with columns to record the day of the activity, the description of the seed/plant, the length of the primary root, and the number of secondary roots. The primary root is the root which emerges from the seed and grows downward. A graph can be drawn to relate the number of days since planting and the number of secondary roots.
Ensure that all students have input into data collection and recording.
Factors: B1, C1, C2, C6, C7, C11, C12, F5
Objectives: 1.2, 3.1
Assessment Techniques: 1, 3, 4, 5, 8, 9
Common Essential Learnings: Numeracy. The length of the primary root and the number of secondary roots for each day can be represented on a bar graph.
Have students bring as many different leaves as possible to the class. Remind them when they are collecting leaves from wild plants to remove the leaves carefully, and to avoid injuring the plant. Along with the leaf, they should bring a description of the plant, and the name of the plant, if possible. The description of the plant should include information like height, shape, arrangement of leaves on stem, and habitat if the plant was growing in its natural setting. The species of plant can be identified using a key or a field book.
Leaves can be preserved in a variety of ways. Laminating using a picture laminator works well. Leaves can be pressed by inserting them between two paper towels and placing the towels under a stack of books for a week or two. Ironing a piece of waxed paper over the leaf will cause some of the wax to go into the pores of the leaf, preserving it. The leaves may also be mounted between two layers of self-adhesive plastic, or between one layer of plastic and a cardboard backing.
When the leaf has been preserved, posters can be produced to show: the leaf; a sketch of the plant from which it was taken; a description of the plant; identification of its habitat; the name of the plant.
Some students may want to undertake this activity using the whole plant, rather than just the leaf. Ensure that students do not gather plants which are protected or are growing in a garden. Plants should be dug from the ground using a garden trowel, and the soil gently dislodged from the roots so that the specimen is as complete as possible. One way to remove the soil is to swirl the root system gently in a pail of water.
Factors: A2, B6, C1, C6, C12, E2, F1, F4, G3
Objectives: 1.3, 2.3
Assessment Techniques: 1, 2, 3, 4, 5, 6, 7, 8, 9
Common Essential Learnings: Independent Learning. Students must make careful and detailed observations which can be compared with and validated by the observations of others. The use of plant identification keys requires logic and complete information. These procedures help the students to see themselves as independent learners.
Students can gather and identify the seed-containing structures of a variety of plants. If the structure is dry (poppy capsule, acorns, heads of grain, grass seed, wild rice, carragana pod, for example), it may be stored in a glass jar. If the structure is moist (tomato, cucumber), it may be displayed on a shelf, or dried and then stored in a jar.
Factors: C1, C6, C12, E2, F4, G3
Objectives: 1.3, 2.3, 3.1
Assessment Techniques: 1, 3, 4, 5

Common Essential Learnings: Critical and Creative Thinking. The diversity of the seed-containing structures can stimulate discussion. Similarities and differences should be noted.
Have students grow several grains of wheat in a plastic cup filled with topsoil. Leave another unseeded cup filled with soil as a control. Once the plants are about 15 - 20 cm high, carefully peel away or remove the cups from the plants and from the control. Ask students to observe and describe how the soil is held together by the plant roots. Compare this to how loosely the soil is held together in the control sample.
Relate this information to the Resources unit. Emphasize the world concerns about soil. Explain the importance of plants in preventing soil erosion. See if students can make a connection between deforestation and an increase in soil erosion. To illustrate this one could make reference to a forested area in Saskatchewan that has been clear-cut, or a rainforest which has been cut and burned.
Factors: A2, B1, B4, C6, C9, C11, C12, F1, F4, F5, G3
Objectives: 1.2, 3.1, 3.2
Assessment Techniques: 1, 3, 4, 5, 8, 9
Common Essential Learnings: Critical and Creative Thinking. The activity provides students with an opportunity to explore how knowledge is created and refined in science. By performing an experiment which establishes how plant root systems help to hold soil together, students can then make inferences about the effects of deforestation.

Grade 5 Science Core Unit: Plant Structure and Function