How do I determine which rate of photosynthesis is slowest?

Answer 1

You'll have to measure or count something. It all depends on what your test subject is.

--You can use electronic sensors to measure the change in oxygen or carbon dioxide in the air around an enclosed plant. The faster the change, the faster photosynthesis is progressing.

-- If you are using the water plant Elodea (Anacharis), you can cut the stem and count the bubbles coming from the cut end. More bubbles per unit time indicates faster photosynthesis because the bubbles will be the oxygen produces during the process.

-- With a water plant you can also put the plants into containers of bromthymol blue solution. Blow your breath into the solution through a straw until the solution just barely changes from blue to yellow. Then time how long it takes to change back to blue. Faster color change = faster photosynthesis.