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TEACH-FLEX Classroom/Remote

How Does It Grow? (At Home)

Grade Level: 2nd Grade

Students work like scientists to test their ideas about what plants need to grow and live by using corn plants as model organisms. Students test growing conditions, such as amounts of water and sunlight.

Teaching the Lesson

Learning Objectives

  • Students will propose answers to the question, “What do plants need to live and grow?”
  • Students will plan and conduct an investigation to test environmental effects on corn seeds (e.g., light availability, water availability, etc.).
  • Students will find patterns in their findings and identify what corn needs to live and grow, forming explanations based on their observations (evidence).
  • Students will conclude from observations that plants depend on water and light to grow in their environments.

Materials

  • We Grow Corn! Book (Available at wegrowcorn.com)
  • Kernels of Knowledge Videos (Available at wegrowcorn.com)
  • Main Idea Worksheet
  • Text Features Worksheet
  • Planning and Recording Worksheets
  • Corn/Sweet corn seeds (if not available, you can use dry edible beans or other larger seeds. The bigger the seed, the better this normally works).
  • Cotton balls or paper towel
  • Ziploc bags or plastic cups you can see through
  • You can use soil instead of the cotton balls; however, it prevents you from SEEING what is happening with the seeds each day.
  • Containers for planting after the seeds germinate
  • Soil

Activity

  • Read We Grow Corn! to find out about corn farming in Kansas. While reading the book complete the Main Idea Worksheet to identify the important concepts about Kansas farming.
  • Next look over the features of the We Grow Corn book such as the index, glossary and bold words and fill out the Text Features worksheet.
  • Watch the six Kernels of Knowledge videos that tie directly to the We Grow Corn book. They provide great opportunities for discussion about what happens on a farm. Find the videos at wegrowcorn.com by
    scrolling to the bottom of the page.
  • Lesson 1: Thinking about plants
    • Introduce the topic and assess student(s) for prior understanding with such questions as:
      • Draw or write down different types of plants.
      • What characteristics do these plants have? What makes a plant a plant? (Guide the discussion, but do not correct or explain to them. This discussion is to get them thinking and comparing ideas.)
      • Instruct students to circle the indoor plants they drew with a black crayon, and the outdoor plants with a red crayon (if unsure, circle with both black and red).
    • Lead further discussion so students explore ideas of what plants need, whether indoors or outdoors, by asking questions such as:
      • Why do you think some plants are grown indoors?
      • Can the outdoors be too dry or too cold for some plants, but not others? Too hot? (Note: Most houseplants originated in tropical or subtropical climates, similar to indoor conditions.)
      • What do indoor plants and outdoor plants have in common?
      • What do all plants need to live and grow? (Create a list on a piece of paper)
    • Guide the discussion toward questions about what plants need to live and grow, whether they’re indoor or outdoor plants. Encourage wonderings and leave questions open for investigation, such as:
      • Do plants need light?
      • Do plants need water?
      • Do plants need soil? (see note below for your own reference, though allow students to ponder this for investigation)
      • Do plants need air?
      • Do plants need other plants?
      • Do plants need food like we need food? (see note below)
      • Do you think plants need the same things that we need as humans? Or do they have different needs?
      • Do plants need the same things when they’re just sprouting from the seed versus once they’ve grown leaves?

NOTE: Not all plants need soil. In fact, while soil provides micronutrients or minerals, soil is not the main source of the matter that plants take in. Rather, water and carbon dioxide (from air) combine through the processes of photosynthesis in plants, creates the simplest building block of plant matter: glucose. Light, water, and air are the most important needs of plants since they provide the elements that form most of the plant’s mass (even when dried). This may seem counter-intuitive, but it is true. Soil mainly provides support for roots and water, as well as a source for micronutrients. See this website for further information on Misconceptions about Plants: https://tinyurl.com/Misconceptions-about-Plants

  • Lesson 2: Plant corn seeds
    In order to germinate seeds, you will need the following supplies:

    • Seeds of any kind, corn is preferred
    • Cotton balls or paper towel
    • Ziploc bags or plastic cups you can see through
    • You can use soil instead of the cotton balls; however, it prevents you from SEEING what is happening with the seeds each day.
    • Containers for planting after the seeds germinate
    • Soil

Directions

  • Wet cotton balls or paper towel.
  • Place the wet paper towel or cotton balls in a Ziploc bag.
  • Add 2-3 seeds to the Ziploc bag.
    Test some of the following options and log them on Planning and Recording Worksheets. (you may want to try multiple seeds in each environment you decide to test)

    • The amount of water you give your seeds by adding different amounts of wet cotton balls or towels.
    • Test the temperature by putting some seeds in a warm place in your house and others in cooler places in your house.
    • The amount of light the seeds receives. Place some in a bright area of your house and others in a dark cabinet.
  • As you observe your seeds each day, keep track of how many days it takes for each seed to germinate and pop through the seed coat.
    Keep in the mind the following as you track the process:

    • How does that seed produce the plants that make corn? Answer: Through a process called germination.
    • What is germination? What do seeds need in order to germinate? Watch Seed Germination YouTube video provided by It AumSum Time.
      • Food for thought: While the video mentions that seeds need sunlight in order to germinate, that is not 100% accurate. Do you know why that is not quite true? Think about for a minute and see if your answer is right. Answer: Seeds are planted in soil. The soil prevents sunlight from getting to the seeds. The sun does however warm up the atmosphere and the soil which the seed is planted in to help in the germination process. Seeds go through many changes as they germinate. Sometimes we might say the seed “sprouts” which is actually the same thing as germinating.
    • Record how many days it takes until the seeds have leaves.
    • Keep track of each bag and compare the results.
    • You can make drawings of your observations each day or you can record your observations by writing down what you see.
    • When the plants have sprouted you can transplant them into soil in a cup to continue growing and eventually transplant them outside. Be gentle as the seedlings are fragile.

NOTE: If you are using different types of seeds, each one has their own germination rate. Corn seeds should germinate in 7-10 days, tomatoes in 5-10 days and beans in 10-14 days. All this is dependent on the amount of moisture available and the soil temperature.

Resources

Optional Resources

This lesson is the work product of the Kansas Corn Commission. Our lessons are written in collaboration with Kansas teachers for use in the classroom. Teachers may copy and share this curriculum. Use of this product for commercial or promotional use is prohibited without express permission of Kansas Corn.

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