Plants Need Light
Place of Learning: 
Garden Classroom
Grade Level: 
Grade 4
Contributor

Mia Villanueva
Berkeley School District Gardening & Cooking Program
Berkeley, CA

Tags: 
Photosynthesis
chlorophyll
Summary: 
This lesson introduces students to the concept of photosynthesis, starting with understanding the role light plays in helping plants make food. The activities invite students to experiment with light absorption by plant leaves. Students make seed starts and place them in different light filled spaces to measure light absorption over time.
Student Learning Goals & Objectives: 

Students will:

  • Conduct an experiment to demonstrate the importance of sunlight for healthy plant growth.
  • Come up with a plan for tracking their experiments over time.
  • Make recycled plant containers using newsprint
Materials & Prep: 
  • Masking tape and markers
  • Leaves for experimenting with light (large and broad are best)
  • Newspaper stripsand mason jars for making seed starts
  • Soil
  • Seeds
  • Popsicle sticks for seed labels
  • Worksheet, Do Plants Need Light – PDF
Procedure Steps: 
1
Making Plant Containers
  1. Review past lessons on what plants need to grow, focusing on light.
  2. Plants are one of the few living things that can make their own food with the help of sunlight. Plants cannot make food without absorbing light.
  3. Ask: How do plants make their own food? (Photosynthesis, starting with absorbing light into their leaves)
  4. Tell students that they will experiment with how plants absorb light.
  5. Direct students to make two recycled plant containers, one for placing in a light filled space and the other for placing in a light absent place, by following these steps:
    • Cut up newspaper in vertical strips.
    • Lay newspaper out so you can roll glass jars neatly along the strips to wrap around the jars.
    • Pull out the glass to leave a newspaper mold.
    • Round the bottom of the newspaper mold by folding newspaper points like a present on the bottom.
    • Fill the mold with soil and place Popsiclesticks with labels of the seeds (suggested seeds are butterfly bushes/milkweed) you will have students plant in them.
    • Have students place seeds and water.
2
Experimenting with Light
  1. This activity will demonstrate that a plant cannot make its own food in the absence of sunlight. Students observe the two plants that they just planted over several weeks.
  2. Direct them to use the worksheet, Do Plants Need Light, page tor ecord their hypothesis and take notes on their observations:
    • Label half of the plants “light” and the others “dark.”
    • Place the plants labeled “dark” in a dark place.
    • Place the other plants outside or by a bright window.
    • Water both sets of plants regularly.
    • Have children sketch pictures of the two plant sets over several weeks and make notes regarding their observations.
    • After two weeks, have students share what they have observed about the “light” and “dark” plants.
3
Student Reflection
  1. What do you think will happen to the plants that don’t get light? What do you think would happen if a plant didn’t get carbon dioxide?
Additional Information
  1. Plant leaves absorb sunlight differently. There are red and blue light wavelengths that plants absorb.
  2. When you see a color, it is actually a color that the object does notabsorb. For example, green plants do not absorb light from the green range.
Download Lesson Materials
English Language Focus: Cause and Effect Statements
  • If plants do not get enough light, they will ____________.
  • If the plants do not get enough carbon dioxide, they will __________.

Academic Standards

Next Generation Science Standards

Disciplinary Core Ideas

LS1.C

Organization for Matter and Energy Flow in Organisms: Within individual organisms, food moves through a series of chemical reactions in which it is broken down and rearranged to form new molecules, to support growth, or to release energy. Plants acquire their material for growth chiefly from air and water.

LS1.A

Structure and Function: All organisms have external parts. Plants have different parts (roots, stems, leaves, flowers, fruits) that help them survive and grow. Different animals use their body parts in different ways to see, hear, grasp objects, protect themselves, move from place to place, and seek, find, and take in food, water and air.

Science & Engineering Practices

Planning & Carrying Out Investigations

Planning and carrying out investigations in 6-8 builds on K-5 experiences and progresses to include investigations that use multiple variables and provide evidence to support explanations or solutions. Conduct an investigation to produce data to serve as the basis for evidence that meets the goals of an investigation. Make observations and/or measurements to produce data to serve as the basis for evidence for an explanation of a phenomenon or test a design solution. Test two different models of the same proposed object, tool, or process to determine which better meets criteria for success

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