Lab
NAME:
01
AP Environmental Science – Population Dynamics
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LAST
DATE:
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FIRST
Can algae save the world?
Goals:
To use algae (Chlorella vulgaris) as a model organism to study about population growth.
Each day you will collect a sample of algae from the class “bioreactor.” You will collect data as a class
using a device called a spectrophotometer. You will record your own data, the class averages and
then graph all of the data.
Lab write-up requirements:
 Annotated graph
 Detailed conclusion
This device measures how much light is transmitted through a particular solution. It will allow us to
measure the “density” of algae in a sample, which corresponds to the population size.
RQ: How does the population size of algae change over a 2-week period?
Hypothesis: Create a hypothesis graph about what you think will happen to our algae over the
course of the next two weeks? Explain your hypothesis.
IV/DV/Controls:
IV: Time (in days)
DV: population size, measured by “optical density” using a spectrophotometer
Controls:
 Rinse cuvettes after each use.
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