Name: _____________________
Date: ______________
Waterweed Simulation of Photosynthesis: Lab #__________
Introduction: In this simulation, you will be looking at the production of oxygen as a plant
photosynthesizes. This procedure can be accomplished by placing elodea plants in water with baking
soda to provide carbon. The plant can then be exposed to varying intensities and colors of light.
Oxygen is measured in the number of bubbles produced by the plant. This simulator addresses three
factors that influence the rate of photosynthesis. Carbon dioxide availability, light intensity, and light
color can all be adjusted in the simulator to determine how each of the factors affects the rate of
photosynthesis.
Part 1: Effect of LIGHT COLOR on the rate of photosynthesis
1.
Predict what color of light (red, blue, green or colorless) you think will cause a plant to produce the most amount of oxygen
2.
bubbles ____________________ and the least amount of oxygen bubbles ____________
Set the simulator to 6.0 light level and 6.0 CO2 level. Adjust the colors to complete the table below. Each trial is a 30 second run.
Part 2: Effect of LIGHT LEVEL on photosynthesis
1.
2.
Predict what light level will have the greatest rate of photosynthesis (intensity 1-10) ______ and the least rate ________
Set the simulator to colorless light and CO2 level to 6.0. Make adjustments to the level of light to complete the data table below.
Analysis Questions
1.
Based on the simulation experiments, what factors can affect the rate of photosynthesis in a plant?
2.
Write the equation for photosynthesis below
3.
What did the bubbles represent in this simulation? Why do bubbles tell you how fast photosynthesis is occurring?
4.
What would you do to develop an experiment to test how the level of CO2 affects the rate of photosynthesis? Identify the
following for your experiment:
a.
Independent variable:
b.
Dependent variable:
c.
Constants (controlled variables- list at least 3):
d.
Why is it important that you keep the variable of CO2 constant throughout your experiment?
5.
6.
Much of the carbon dioxide produced by green plants is not excreted as a metabolic waste because it
A) can be used for photosynthesis
C) is needed for cellular respiration
B) is too large to pass through cell membranes
D) can be used for the creation of proteins