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     Supporting Changes in Thinking  Supporting Changes in Student Thinking

     

    Investigation 1: Brassica Seeds Investigation 2: Grass & Grain Seeds
      1.1 Introducing Recording
    1.2 Planting Brassica
    1.3 Observing Brassica Growth
      2.1 Lawns
    2.2 Mowing the Lawn
    2.3 Wheat
           
    Investigation 3: Stems Investigation 4: Bulbs & Roots
      3.1 Rooting Stem Cuttings
    3.2 New Plants from Cuttings
    3.3 Spuds
      4.1 Bulbs
    4.2 Planting Roots

     


    Investigation 1: Brassica Seeds

    Each student plants tiny rapid-cycling brassica seeds in a planter cup. The cups are kept in a tray under continuous light. The brassica plants grow and develop for a month while students care for them, observe, and record the complete life cycle.

    • Science & Engineering Practices: (Analyzing and Interpreting Data) Students make and record observations of plant growth. Use the student data chart provided but paste into science notebooks. Continuously add to this data throughout the investigation and allow students to share and discuss their thinking about cause and effect.
    • Crosscutting Concepts: (Cause and Effect) Students are able to discuss the changes the plants go through and how may be the cause of these changes.

    1.1 Introducing Recording

    Key Activity - What Students Do

    Students prepare for several weeks of plant growing investigations. They discuss what they know about plants and prepare a class calendar to keep track of growth and development. The set up their Science Journals as a place to record their observations, thoughts and questions.

    Key Learning/NGSS Connections - What do Students figure out?

    Scientists carefully record observations.

    Big Idea - Focus Questions

    How do scientists investigate questions they have?
    Are Plants Alive?

    Connection to Anchoring Phenomenon

    The avocado pit is the seed for a plant, and plants are living organisms.

    Formative Assessment Task

    Students think of a plant they have seen recently.
    Draw this plant and label any parts that they know.
    Is It a Plant? Formative Assessment Probe from Uncovering Student Ideas in Science, Vol 2, pg 93.
    Notebook entry: Date/observations of plant with labels.

    1.2 2 Planting Brassica

    Key Activity - What Students Do

    Students plant rapid-cycling brassica seeds in soil and place them under a lamp where they will receive continuous light.

    Key Learning/NGSS Connections - What do Students figure out?

    If the seed germinates and grows then it was alive.

    Big Idea - Focus Questions

    Are Seeds Alive?

    Connection to Anchoring Phenomenon

    Just as Brassica seeds grow into Brassica plants, the avocado seed grows into an avocado plant.

     

    1.3 Observing Brassica Growth

    Key Activity - What Students Do

    Students observe germination, growth, flowering and seedpod formation. The investigation culminates in the harvesting of seeds, providing an introduction to the concept of life cycle in plants.

    Key Learning/NGSS Connections - What do Students figure out?

    Plants have leaves, stems, roots and flowers that produce seeds.

    Big Idea - Focus Questions

    Is it a flowering plant? What parts are needed to make a whole flowering plant?

    Connection to Anchoring Phenomenon

    The growing plant has similar parts: roots, stem, leaves.

    Formative Assessment Task

    Brassica A or B matching page Brassica Life Cycle Page.

    Investigation 2: Grass and Grain Seeds

    Students plant miniature lawns with rye grass and alfalfa. Periodically they mow the lawns and observe the response of grass and alfalfa to cutting. They plant individual wheat seeds in clear soda straws and observe in detail how grain seeds germinate and grow.

    • Science & Engineering Practices: (Constructing Explanations and Designing Solutions) Students will need to collect ongoing data from their observations to determine why grass continues to grow and alfalfa does not (Investigation 2.2), as well as how wheat grows without soil (Investigation 2.3).
    • Crosscutting Concepts: (Cause and Effect) Students cut the lawn (cause) and observe future growth of the plants (effect) to find patterns that support or refute their explanations.

    2.1 Lawns

    Key Activity - What Students Do

    Students make a miniature lawn by planting the seeds in cups of soil, watering the seeds, and providing nutrients in the form of liquid fertilizer. The lawns are placed in the light. Students observe and record changes in plant structures over time - growth of stems and leaves. They observe that the two kinds of plants look different as they grow.

    Key Learning/NGSS Connections - What do Students figure out?

    Plants need air, water and light to grow.

    Big Idea - Focus Questions

    What are the needs of plants? How do living organisms interact with their environment?

    Connection to Anchoring Phenomenon

    All plants need certain conditions for the seeds to grow. In the avocado, it needed to be partially submerged in water.

     

    2.2 Mowing the Lawn

    Key Activity - What Students Do

    When the lawn plants are about a week old, students mow the lawns and observe how the different plants grow and change. The grass blades continue to grow, but the alfalfa plants don't survive without their leaves. Cause and effect are introduced.

    Key Learning/NGSS Connections - What do Students figure out?

    Grasses grow from the bottom, other plants grow from the top.

    Big Idea - Focus Questions

    How do living organisms interact with their environment? Do all plants grow back after being cut?

    Connection to Anchoring Phenomenon

    Avocado plants grow like the alfalfa. If the leaves get removed, the plant can’t make its own food, and dies.

    Formative Assessment Task

    Notebook entry: Why did the alfalfa plants die after we mowed our lawns? Why did the grass live? Growing and Mowing a Lawn (Sequencing page from FOSS)

    2.3 Wheat

    Key Activity - What Students Do

    Each student observes the growth of a single wheat seed (another type of grass) in a clear straw. Students compare the growth of the root to the growth of the stem in terms of structures, direction, timing, and amount of growth. They read about this important grain that serves as an important food source for people.

    Key Learning/NGSS Connections - What do Students figure out?

    Plants need nutrients from the soil or another source.

    Big Idea - Focus Questions

    How do living organisms interact with their environment? Do plants need soil to live?

    Connection to Anchoring Phenomenon

    First comes the root, then the stem. The material and energy for this initial growth is contained in the seed. The idea that there is a lot of energy stored in seeds can help explain why seeds are good food. A fun project is to get some mature wheat and grind it into flour and make cookies or bread.

    Formative Assessment Task

    “Is It Food for Plants?” formative assessment probe from Understanding Student Ideas in Science, Vol.2, pg. 113
    Data recording sheet (date, draw, and label)
    Discussion:
    • Observations of wheat growth
    • Why did some of the seeds not grow?
    • Where does this plant get its nutrients?
    “Needs of Seeds” formative assessment probe from Understanding Student Ideas in Science, Vol 2, pg. 101.

    Investigation 3: Stems

    Investigation 3: Stems - Students are challenged to make a new plant from an older plant. They put sections of stems from mints, ivies, and other plants into water and look for evidence that a new plant is forming. Stem pieces that develop roots are planted to make new plants. Students also plant pieces of potatoes (modified stems) and observe them grow into plants.

    • Science & Engineering Practices: (Planning and Carrying Out Investigations) Students bring in stem cuttings to observe growth of new plants without seeds. As students’ progress to Parts 3.2 and 3.3, they plan the investigation using what they know about how plants obtain the nutrients they need to plan a proper environment for the promising plant
    • Crosscutting Concepts: (Stability and Change) Students predict what will happen to stem cuttings placed in water.

    3.1 Rooting Stem Cuttings

    Key Activity - What Students Do

    Students are challenged to make a new plant from an older plant. Students observe a stem with leaves from a common houseplant or ivy and observe the nodes. They learn that a node is a place on the stem where a leaf or branch will grow. With that knowledge, students make a cutting of their own design to see if it will grow into a new plant. Students will know if the cutting grows new roots and begins to grow from the node. Cuttings are placed in water and observed.

    Key Learning/NGSS Connections - What do Students figure out?

    Stems can also produce new plants with the right environment.

    Big Idea - Focus Questions

    What does it mean to be alive? Is the seed the only part from which new plants can grow?

    Connection to Anchoring Phenomenon

    Many plants we use in agriculture are made from “cuttings” from existing plants. A stem is cut and new roots are encouraged to grow on the stem.

    3.2 New Plants from Cuttings

    Key Activity - What Students Do

    Students select the stems that sow promise for developing into new plants and plant them in soil.

    Key Learning/NGSS Connections - What do Students figure out?

    Water, nutrients and air will keep our plant alive.

    Big Idea - Focus Questions

    How do living organisms interact with their environment? What will keep our new plant alive?

    Connection to Anchoring Phenomenon

    Once the stored energy and material in the seed is “used up” the plant needs to get material and energy from the environment.

    3.3 Spuds

    Key Activity - What Students Do

    Students are introduced to another plant stem, a potato. Students observe the nodes (eyes) on the potato. Students plant a piece of the potato with the node in potting soil and observe growth and change over time.

    Key Learning/NGSS Connections - What do Students figure out?

    Potatoes are modified stems that can form roots.

    Big Idea - Focus Questions

    What is a stem? How do we know if a potato is a root or a stem?

    Connection to Anchoring Phenomenon

    Potatoes are specialized stems, and so they are good for creating new plants. They are NOT seeds, so they don’t have the same internal structure as the avocado plant.

    Formative Assessment Task

    Notebook entry: Observations of plant growth. How do we know that we grew new plants (not old plants)? Why didn’t all the cutting grow roots?

    Investigation 4: Bulbs & Roots

    Students plant onion bulbs or garlic cloves in moist cotton and observe as they develop into new plants. They plant parts of roots—carrots and radishes—to discover which parts will develop into new plants.

    • Science & Engineering Practices: (Constructing Explanations and Designing Solutions) Students observe growth of bulbs and edible roots to determine if they are alive.
    • Crosscutting Concepts: (Cause and Effect) Students predict what will happen to bulbs exposed to moisture, but not soil; and then roots exposed to vermiculite.

    4.1 Bulbs

    Key Activity - What Students Do

    Students are introduced to common bulbs (garlic or onion bulbs) and learn that a bulb is a short piece of stem with a bud at one end and roots at the other. Students provide water for the bulbs and observe growth of roots, stem, and leaves. Bulbs, produced by the mature plant, are one more way that some plants reproduce.

    Key Learning/NGSS Connections - What do Students figure out?

    Bulbs are modified stems like potatoes.

    Big Idea - Focus Questions

    What is a stem? Are bulbs alive? How do you know?

    Connection to Anchoring Phenomenon

    Bulbs are also modified stems – they have roots at one end and grow leaves at the other. Bulbs are a way that a plant stores energy over the winter. Avocado seeds are not bulbs.

    4.2 Planting Roots

    Key Activity - What Students Do

    Students investigate plants with edible roots – carrots and radishes. After observing the parts- leaves, stems, and roots – students cut the plants into three or four parts and plant them in vermiculite to see if they will produce new plants. After observing the changes for 2-3 weeks, students draw conclusions about the likelihood of producing new plants from parts that are usually found underground.

    Key Learning/NGSS Connections - What do Students figure out?

    New plants will grow from roots.

    Big Idea - Focus Questions

    What is a root? Will roots produce a new plant like a stem?

    Connection to Anchoring Phenomenon

    Some plants store energy in their roots. If the top part of the root (which is the stem) is given the correct conditions, roots will form and leaves will start to grow as it turns into a new plant.

    Formative Assessment Task

    Growing Bulbs (FOSS page): Before and after observations of a bulb. Discussion: Observation of growth over time. Predict which part of the radish or carrot will grow (FOSS page).

     

    The Boston Public Schools has a series of YouTube videos for teachers that give an overview of each of the Investigations: