Expert: Walter Hintz - 1/30/2008

Question
QUESTION: Hello I need help! Okay, I'm in the eighth grade and I have to have an expert that I can contact throughout my entire experiment. I need an expert in botany in two days who can verify and agree through email that you can help me and answer some questions for me! Please, all the other experts I've tried can only answer one question! If you can't, thats okay but do you know an expert who could help me? My investigative question is: How does the amount of water pollution affect plant growth? Specifically the growth of a pea plant. But anyway, get back to me as soon as you can??? Thank you SOOO much.

ANSWER: Hi mariah; Let me know more about your project.  What is your hypothesis and tell me how you have designed your experiment

---------- FOLLOW-UP ----------

QUESTION: Hi,

okay my hypothesis is:

If there is more polluted water fed to the plant then the plant will grow slower because the plant needs clean, pure water.

The manipulated variable: Amount of polluted water.

Levels of the MV: Water oil and antifreeze
[I'm doing 3 trials for each level of MV]

Responding Variable: Plant Growth

I was thinking of using a pea plant but I'm not sure that would work out with measuring height, so I was wondering; should I use a pea plant and just measure how long it takes for a full pod to develop, or should I change the type of plant so it will be easier to measure plant height?


-Mariah

ANSWER: Sounds ok Mariah.  Make sure you use controls with respect to amounts of liquid, type of soil, amount of light and so forth.  Have you established the quantities of pollutants to add to the water?
 I also suggest that you use bean plants.  they grow taller and are easy to measure.  Peas tend to coil.
Keep me informed

---------- FOLLOW-UP ----------

QUESTION: Okay thanks so much! I'll change it to a bean plant, thanks! About the quantities, I haven't gotten to that yet...what do you suggest? I don't know that much about plants and I'm trying to make my experiment as best as it can be so I can get good results. I'll check in later. bye!

-Mariah

Answer
If I understand it you are varying the amounts of water and not the amount of pollutants.  Is this correct?  If so I think you should consider varying the amount of pollutants in the water and not the amount of water.  You mentioned oil and antifreeze. In other words use 4 cups of water. To cup a add a small amount of pollutant (say 2 ozs) To cup b double it and to cup c triple it and to cup d none (this is your control) You can vary these amounts.  Got it?  Does this make sense?