Plants and Light

This lesson plan includes a step by step guide to the experiment to show that plants need light.  By cutting a window in the shoebox, the students should be able to observe the plants growing towards the window regardless of which way the window faces.

 

Standards & Objectives

Learning objectives: 

Students will:

  • relate the presence and absence of light to the rate and characteristics of plant growth (e.g. size and color of leaves.)
  • demonstrate that plants grow towards sunlight (positive phototropism.)

 

Essential and guiding questions: 

Do plants need light to stay alive? 

Do they need light to photosynthesize?

Lesson Variations

Blooms taxonomy level: 
Applying
Extension suggestions: 

For individual students or student teams: use two bean plants of identical height, both relatively vertical in growth. Construct two covers from sneaker boxes, by removing a square window of approximately 2 inches from one end of each box. Be sure to keep the windows in both boxes as identical as possible. Cover the plants with the boxes, being sure to allow a couple of inches for upward growth, blocking out all the light with the exception of that coming through the 2" window. Place both plants on the same windowsill, where they will receive approximately the same amount of sunlight, but orient one hole left, and one right. Have students predict what they think will happen, and plot results over time. (In a few weeks, one bean plant should be growing noticeably left, and one noticeably right.)

Helpful Hints

Materials needed:

  • for teacher demonstration: potted geranium, bean plants, or other easily obtainable plant
  • cardboard
  • per student team:
  • 2 bean plants of equal size
  • 2 sneaker boxes

Note: If you plan to do these light activities with multiple classes, it might make sense to germinate and grow several bean plants, and let them reach 3-4 inches in height

 

References

Contributors: