What Do Leaves Do?

4.1 based on 13 ratings

Updated on Feb 26, 2014


Life Science


Elementary School

Difficulty of Project



Less than $50

Safety Issues


Material Availability

Use a houseplant and supplies found at home or purchase from a local retailer.

Approximate Time Required to Complete the Project

1 week


This experiment teaches kids the different functions of a leaf.

  • Potted plant
  • Paper
  • Plastic wrap
  • Paperclip
  • Rubber band
  • Camera
  • Printed Photos


Leaves provide food and air to help a plant stay healthy and grow. Through photosynthesis, leaves turn light energy into food. Through pores, or stomata, leaves “breathe” in carbon dioxide and “breathe” out oxygen. Leaves also release excess water, much like we sweat. In this experiment, kids will test what happens to a leaf when covered with different materials.

Research Questions
  • What is photosynthesis?
  • What is transpiration?
  • What is respiration?
  • What makes a plant green?
  • What are the different parts of the leave that help with photosynthesis, transpiration and respiration?
Terms, Concepts and Questions to Start Background Research
  • Photosynthesis – the process by which plants turn light into food that can be used by the plant to grow
  • Transpiration – the process of a plant releasing water vapor through pores called stomata
  • Respiration – the process of a plant breathing
  • Chloroplast – structure within the plant where photosynthesis occurs

  • Get a healthy green potted plant with large leaves.
  • Take photos of your plant before starting the experiment.
  • Cover the tops of 2 leaves with a piece of paper using a paperclip to secure the paper.
  • Cover 2 leaves entirely with plastic wrap. Use a rubber band wrapped around the stem to secure the plastic.
  • Water the plant and place it in a sunny location.
  • Check and take photos of the plant daily for 5 days. Write down any changes in the leaves or other observations you make.
  • On day 5 take the paper and plastic off the leaves. What happened to the leaves? Why did this happen? Take pictures and write down what happened to the leaves.
  • Display the plant and your photos and notes at the science fair.


Nova Online: Illuminating Photosynthesis http://www.pbs.org/wgbh/nova/methuselah/photosynthesis.html

Cupertino Union School District: Leaves http://www.cupertino.k12.ca.us/westvalley.www/programs/natural_science/4thGrade/Leaf.htm

Biology 4 Kids: Plant Basics http://www.biology4kids.com/files/plants_main.html

Jennifer L. Tuso has over 10 years experience developing and teaching science enrichment programs to all ages, from preschoolers to high school students. She holds a degree in Environmental Studies with a minor in Biology from CSUS. As a freelance writer, she enjoys sharing her teaching experiences, mishaps and adventures.