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Bottle Experiments with Mung Beans

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Curricular Materials to Accompany the McIntosh Apple Development Poster
Distributed by the Education Committee of the Botanical Society of America
Posted March 2001

Grade Levels: 6-8; 9-12

Abstract: Plants respond behaviorally to changes in their environment by changing patterns of growth.  The purpose of this lab is to explore how environmental features like light and volume of air influence growth in mung bean sprouts.  Students will make predictions about the relationship between growth and environment, and test their predictions by growing sprouts in various sized plastic soda bottles.

At the end of this exercise, students will be able to:

    A seed contains its own life support system.  When stimulated to germinate, seeds use stored food reserves to grow into sprouts.  A sprout is a tender, often edible, seedling that is produced following seed germination.  As the sprout begins to develop and use up its stored reserves, the seedling needs light and carbon dioxide to continue growth.
    In this experiment, students will examine how the amount of carbon dioxide and light changes the growth of a mung bean's sprout.  The equation of photosynthesis shows the relationships among carbon dioxide, light, and growth:

6 CO2 + 12 H2O ---light----> C6H12O6 + 6 O2 + 6 H2O.

In this expression, C6H12O6 represents simple sugars that are used by the plant for energy and structural materials like wood.  In other words, they are required for growth.  Carbon dioxide (CO2 ) is necessary for plants to form those simple sugars.  Plants have the capacity to use CO2 from the atmosphere for this purpose.  If students experimentally vary the amount of available carbon dioxide or light, they can observe their effects on plant growth.  In this exercise, seedlings are grown in plastic soda bottles.  The amount of CO2 varies with the volume of the bottle and light is manipulated using aluminum foil.  Additional volume will allow the seedlings to grow to a greater size. 
    Light will have different effects depending on how long the sprouts are allowed to grow.  In all cases, sprouts grown in low light will be longer than sprouts grown in more intense light.  However, after the food reserves available in the seed are used up, a plant grown in the dark will cease to grow and will be outgrown by the plants grown in the light.

    In addition to reinforcing plant science content, this lab expects students to apply the scientific method.  After learning basic information about growth and photosynthesis, students formulate a hypothesis about the growth of their mung bean sprouts in different treatments.  After they have gathered and compiled the data,  students will compare their experimental results to their original hypothesis and draw appropriate conclusions.


    Note:  Mung beans should not be soaked in water; they should be moistened with the damp paper towels.  The bottles should not have excess water in them prior to the lab. 



Introductory plant biology books will discuss germination and growth of seedlings.  Several are listed below. 

  • Raven, P.H., R.F. Evert, S.E. Eichhorn. 1998. Biology of Plants. Worth Publishers Inc., New York.
  • Stern, Kingsley R. 2000.  Introductory Plant Biology, 8th ed. McGraw Hill, Dubuque, IA.
  • Uno, Gordon, R. Storey, and R. Moore 2001.  Principles of Botany, 1st ed. McGraw Hill, Dubuque, IA.
  • Burnie, David. 2000. Plant. Dorling Kindersley Eyewitness Books, New York.


For more information about sprouts see the International Sprout Growers Association


This activity is based on an exercise presented by Ken Blom, Niskayuna School District, Niskayuna, NY and was developed and edited by Amy Russel and Steven Rice, Department of Biological Sciences, Union College, Schenectady, NY.