Amazing bean races

🇧🇶

Student worthiness
Tested with some success.

Primary biological content area covered

 * Plant growth
 * Seedling morphology
 * Hypothesis testing
 * Experimental design
 * Line graphing
 * Introductory statistics

Teacher's equipment

 * Watering can

Student group materials

 * Glass jars
 * Potting soil
 * Thick absorbant paper
 * Scissors
 * Disposable diaper
 * Bean seeds (we used bush beans)
 * Rulers
 * Labeling tape or stickers
 * Waterproof markers

Description of activity
In this activity students compare bean growth under two conditions. In the process they can generate data for a range of graphing activities, examine seedling morphology, test their hypotheses regarding plant growth, and expand to statistical analysis if appropriate for their age.

Soil and paper treatments

 * 1) Cut paper to line half of the jars
 * 2) Roll the paper into a cylinder and place in jar
 * 3) Loosely pack the soil into the empty space inside the paper cylinder; this will hold the paper against the jar
 * 4) Use a ruler to push two or three beans halfway down the side of the jar between the paper and the glass (side beans)
 * 5) Leave the ruler in place or attach a paper ruler to the outside of the jar to facilitate measurement
 * 6) Number the beans with tape or stickers on the outside of the jar
 * 7) Add one bean into the soil directly just under the surface (center bean)
 * 8) Water the soil

Diaper treatment

 * 1) Tear the diaper apart; save the absorbent inner material; dispose of the exterior fabric and liner
 * 2) Place the absorbent material (spun cellulose) in the jar to about 1/3 depth
 * 3) Slowly add water and mix until a firm gel results (you may need to vary the proportions; experiment and see what works)
 * 4) Use a ruler to push two or three beans halfway down the side of the jar near the glass (side beans)
 * 5) Number the beans with tape or stickers on the outside of the jar
 * 6) Add one bean into the center of the gel just under the surface (center bean)
 * 7) Leave the ruler in place or attach a paper ruler to the outside of the jar to facilitate measurement

Data collection
Decide upon a rough schedule for data collection and keep to it as far as possible. Recognise that schedule shifts, school closings, and other unforeseen circumstances may disrupt your data collection. When making side-by-side comparisons it matters more that the data be collected at the same time and in the same way than the specific pattern of data collection. That said, I suggest the following approximate schedule:
 * 1) Try to track the number of days to germination for each bean
 * 2) Once germination has occurred, track plant height at regular intervals (perhaps daily, or every two days); record the date and plant height in each case
 * 3) Determine some end point for the side beans and center beans and measure final height

Potential pitfalls
Glass jars may not be the best choice for all student groups. Clear plastic drink bottles cut off at the neck in advance by the teacher are a great substitute. We learned on running this experiment that bean seeds did not even germinate in the spun cellulose that is typically used in diapers. The cellulose appears (we suspect) to hold water so well that none of it is available for germination. So, if you want a spectacular difference between treatments; this might be the experiment for you.

Math connections
Both the end point data and the time until germination are great for averaging, bar graphs, measures of data spread (standard error perhaps), and tests The timed growth data are ideal for line graphs, and if you so choose, regression.

Literature connections
A seed is sleepy by Dianna Hutts Aston and illustrated by Sylvia Long is both beautiful and informative. It is a rare combination of well-written and accurate scientific content and great art; Chronicle Books, San Francisco, CA, 2007

Cole, Joanna. 1997. The Magic School Bus Gets Planted: A Book About Photosynthesis. Scholastic Inc.

-To go along with the Magical School Bus book the students could test bean plant growth under different conditions. The book gives an overview of photosynthesis in a manner children can understand. They could hypothesize what would result in the best bean stalk growth; artificial light, sunlight, and different amounts of water given to each plant. Students would observe the plant growth and evaluate the best conditions to support a bean plant.

Connections to educational standards
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What educational standards does this activity address? Enter the relevant section numbers here. Vermont standards can be found in web links at the bottom of this page. Feel free to add links to other standards.

Next steps
Because the diaper material was a poor growth medium for seeds, I wonder if a 50/50 soil/diaper material mixture might be of intermediate potential as a growth medium? In addition, if students hypothesize that growth will be better in the diaper gel concoction, it is a valuable lesson to see that rejecting their hypothesis is in fact good and successful science to be rewarded with a high grade.

Citations and links
While brand new ideas are very valuable and most welcome here, tried and trusted ideas of others will probably make up the bulk of the material on this site. It is important to respect the copyrights of others, and also to acknowledge their ideas. A full citation to published materials is essential and also useful. If there are online materials that would be useful to supplement your program, link to them from here.