Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Transpiration Experiment 
Name: Bernadette
Location: N/A
Country: N/A
Date: N/A
Question:
Hi! I am a high school student who is doing a science project concerning the transpiration of plants. My question is "Do plants transpire at the same rate under different sources of light?" For my experiment I am planning to use 6 pansies and plant them in 6 2-liter bottles by cutting off 2/3 of the top. After planting them and watering them I will reattach the tops to the bottoms and place one under an incandescent lamp, one under fluorescent light, and the control under natural sunlight (the three others I will use to repeat my steps for more accurate results). After three hours I plan to remove the tops the measure the amount of water.

Now, what I am wondering is do you have any suggestions on how I could show my results? In the procedure, do you see anything I should change? I also read that heat and humidity affects transpiration how would I be able to tell how much the light alone affected the plants?


Replies:
Something I would consider is that evaporation is not being controlled. You might try setting up a simple transpirometer, placing the stem of your sample plant into a tube with water that is otherwise sealed. Measure the amount of water lost from the tube - it could only leave via transpiration. You also need to control for surface area of the leaves - you might need to find a way to convert the mass of the leaves to surface area, or trace each leaf onto graph paper and measure the surface area by measuring the space on the graph paper.
Good luck -

ellen mayo

Dear Bernadette,

The following may be helpful.
http://explorer.scrtec.org/explorer/explorer-db/html/783750870-447DED81.html

Sincerely,

Anthony R. Brach

When beta decay occurs, the electron produced has quite a lot of kinetic energy. Enough, in fact, to exceed the attraction between the newly-produced electron and proton, so the electron flies away.

Rich Barrans
Argonne National Lab

As with all science experiments, the key is to keep all the variables but one the same, if heat, humidity, and all other conditions except the light are the same, then results must be due to the different light.

J. Elliott


Click here to return to the Biology Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory