Complete the following in your journal. Feel free to discuss and work with a partner of
your choice.
During April, plankton tows (dragging a fine net under water) were made of Puget Sound
each day. The relative numbers of 2 types of organisms captured in the plankton net were
counted and are listed below.
Date
in
April
1
5
10
15
20
Number of
zooplankton
Number of
phytoplankton
32
33
43
192
240
380
525
706
910
956
a. Graph the data.
b. Calculate the overall percentage change for the April data.
c. Is the change for the zooplankton the same as the phytoplankton?
d. Calculate the percentage change for other time periods for both the zooplankton and
phytoplankton. Describe the changes. Hint: Is the change constant? Is there a period
which the change is greater than another?
e. Develop an explanation for the pattern that the numbers of both organisms increased.
However, the number of zooplankton did not really increase until after the
phytoplankton population increased.
f. Explain how you could “test” your explanation (i.e. hypothesis) using “good”
science. In other words, set up a “controlled” experiment. Identify a manipulated and
responding variable, account for multiple trials (average results), control other
variables, use a control/experimental group, and include validity measures (i.e. “clean”
equipment, “rinse”, etc.).
Complete the following in your journal. Feel free to discuss and work with a partner of
your choice.
During April, plankton tows (dragging a fine net under water) were made of Puget Sound
each day. The relative numbers of 2 types of organisms captured in the plankton net were
counted and are listed below.
Date
in
April
1
5
10
15
20
Number of
zooplankton
Number of
phytoplankton
32
33
43
192
240
380
525
706
910
956
a. Graph the data.
b. Calculate the overall percentage change for the April data.
c. Is the change for the zooplankton the same as the phytoplankton?
d. Calculate the percentage change for other time periods for both the zooplankton and
phytoplankton. Describe the changes. Hint: Is the change constant? Is there a period
which the change is greater than another?
e. Develop an explanation for the pattern that the numbers of both organisms increased.
However, the number of zooplankton did not really increase until after the
phytoplankton population increased.
f. Explain how you could “test” your explanation (i.e. hypothesis) using “good”
science. In other words, set up a “controlled” experiment. Identify a manipulated and
responding variable, account for multiple trials (average results), control other
variables, use a control/experimental group, and include validity measures (i.e. “clean”
equipment, “rinse”, etc.).