Elodea (Waterweed) Simulation
Name:___________________________Date Due:________
Introduction: In this simulation, you will be looking at the production of oxygen as a plant (the
waterweed) photosynthesizes. Carbon dioxide utilization can be measured by examining the number
of bubbles produced by the plant since the rate of oxygen production can correspond to the amount
of carbon dioxide used . Three factors that influence the rate of photosynthesis can be adjusted in the
simulator to determine how each affects the rate of photosynthesis. Go to water weed lab link on
website to do this lab. Please print this lab as well as graph paper and submit.
Effects of Light Colors on the Rate of Photosynthesis
Set the simulator to 6.0 Light Level, and 6.0 CO2 Level. Adjust the colors to complete the table.
Light Color
Number of Bubbles 1. Based on the data, what
(Light = 6.0 | CO2 =
color of light results in the
6.0)
fastest rate of photosynthesis?
Red
Blue
______________________
Green
Colorless
Effects of Light Levels on Photosynthesis
Set the simulator to colorless light and CO2 level to 6.0. Make adjustments to the level of light to
complete the data table.
Light Level
1.0
Number of Bubbles
2. Based on the data,
(Light = Colorless | CO2 = 6.0 ) what light level results
in the fastest rate of
photosynthesis?
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
______________
Effects of CO2 Levels on Photosynthesis
Develop an experiment to test how the level of CO2 affects the rate of photosynthesis. (Test the
different levels of CO2). Construct a data table in the space below that shows the data you collected.
Make sure to include information such as the color of light, light intensity, level of CO2 and the
amount of bubbles produced. (Use the previous experiments as a guide)
Data Table
3. Based on the data, what level of CO2 results in the fastest rate of photosynthesis?
_________________
GRAPHING:
•
Using the data from the Effects of Light on Photosynthesis experiment, make a line graph
to represent the light level versus the number of bubbles produced. Graph paper
recommended. YOU MUST ATTACH GRAPH TO THIS LAB.
•
For each point of data, make a point surrounded by a small circle to show any possible error
that could exist. Draw an triangle around each data point.
•
Make sure all your points are connected!
ANALYSIS
4. Based on the simulation experiments, what factors can affect the rate of photosynthesis in a plant?
5. Write the equation for photosynthesis (use your book or online resources if you don't know it).
6. What are the bubbles you are measuring in this lab? Why do the bubbles tell you how fast
photosynthesis is occurring?
7. Why is it important that you keep two variables constant (such as light level and color) while you're
testing how a third variable (CO2 Level) affects photosynthesis?
8. What settings can you put the simulator on to get the MAXIMUM rate of photosynthesis?
9. Why is the use of the word “colorless” inaccurate? (Explain thoroughly)
10. What are the approximate wavelengths of light produce the maximum rates of photosynthesis?
___________________nm
___________________________nm
11. Make a list showing the route for the diffusion of oxygen as soon as it is produced until its final
exit out of a C-3 plant. Draw an arrow to link each word showing the direction of oxygen diffusion.
12. Baking soda was added to the water in this experiment initially. Why do you think that baking
soda was used (hint look up baking soda and determine what happens to it once it is mixed with
water).