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Name ___________________________________
Block _____
Objective: to observe how different variables affect the rate of photosynthesis in a water plant
Go to the following site: http://www.saddleworth.oldham.sch.uk/science/simulations/waterweed.htm
Procedure: There are many variables that you can use to get information from this simulation. It is important that when you are testing a given variable it is the only variable (thing) that is changed.
1.
For a trial run, set the CO2 and light level to about 5.0. Click on the start button and watch the number of bubbles that appear. After counting the bubbles for 30 seconds, it will record them on the chart.
2. Notice that you can run this experiment in “real time” or “fast time”. You can also change the color setting so that your light filter can be white, green, blue or red.
2
5.0
0
5.0
1.0
3.0
8.0
10.0
5.0
5.0
5.0
5.0
5.0
5.0
5.0
10.0
5.0
5.0
0
5.0
5.0
5.0
5.0
1.0
3.0
8.0
10.0
5.0
5.0
5.0
10.0
White
White
White
White
White
White
White
White
White
White
White
Blue
Green
Red
White

Use the simulator to answer and interpret the questions that appear below.
(Answer in Complete Sentences)
1.
How does color affect the rate of photosynthesis?
2.
How does light intensity (light level) affect the rate of photosynthesis?
3.
How does the amount of CO
2
present affect the rate of photosynthesis?
4.
What are the bubbles you are measuring in this lab? (think about the photosynthesis equation)
How can the bubbles tell you how fast photosynthesis is occurring?
5.
Why is it important that you keep two variables constant (such as light level and color) while you are testing how a third variable (CO2 level) affects photosynthesis?
6.
What settings can you put the simulator on to get the maximum rate of photosynthesis?