advice on science project idea?

[Christina123]

Hi
I'm in grade 10 and I think I'll do my science fair project on the effects of 3 different herbicides and pesticides on the rate of photosynthesis and it's effect on cyanobacteria. I'll observe how it affects the cyanobacteria and measure its rate of photosynthesis. Is this idea appropriate for my age or should I try something harder? I think it would be more interesting if I could test the effects of herbicides and pesticides on tadpoles and cyanobacteria. But I might not be able to use tadpoles because of the animal restrictions.

[JinSoul]

I think you have a great idea for a science project. You just have to utilize your knowledge and make experiment with your project in unique ways. I can see that you are trying to introduce more variables into the project which is a great start.
How about trying to introduce ethical issues into your project as well-i.e. the use of herbicides and its effects on pollution and plant life.
Also do not be discouraged to shut out other ideas if they come along.
Here are some sites that might help with your current topic of choice:
http://www.alive.com/175a1a3.php
http://science.jrank.org/pages/3306/Herbicides.html

This is an up-to-date news site full of new and interesting scientific discoveries:
http://www.sciencedaily.com/

[Christina123]

Hey
Thanks for the links. I can see they will be useful. I was just wondering would it be better to use leaf samples and expose them to herbicides/pesticides such as 2, 4-D and measure their rate of photosynthesis or try different amounts of herbicides/pesticides plants for about 2 months? Then I could observe the overall effects on their health as well as photosynthesis compared to the control. I was thinking I would use a common plant that is very sensitive to its surroundings, exposed to humans and pesticides so that my project is more relevant. Or I could possibly use many different types of plants to see which one is affected most. That would involve many treatments and trials though. What kind of plants do you reccomend? I have started reading about actual studies but they are often extreamly complicated (for me anyway) and involve having to translate a lot of jargon. I could also do the cyanobacteria thing as a side along project I guess. I wanted to know if they can adapt to the chemicals after a few generations as well. I was reading about how cyanobacteria affect coral reefs and so I think information about them is quite important. But I actually became interested in this topic while I was researching the use of Agent Orange in Vietnam. How could I involve this aspect as well as other social/health concerns in my project?

For measuring the rate of photosynthesis I think I could use a spectrophotometer (too expensive? but I may have access to one at the local university if my teacher can set me up with a mentor or something) or try something simpler like a floating leaf assay. What do you think is the best method of doing this?

Thanks for your time

[adance]

If you are interested in public health concerns, maybe you want to use plants that people depend on? Like soybeans or corn or something that we eat a lot of.

One way to measure photosynthesis is by the CO2/O2 concentration. Oxygen air bubbles will come out, for example. There's something called bromophenol blue that turns green in the presence of CO2 (because CO2 changes the pH), if I remember my high school biology correctly.

amber

[adance]

Or maybe it's bromothymol blue. It's been a while.