Ohio Graduation Test for Science – March 2007
Annotated Item 26
Standard and Benchmark Assessed:
Standard:
Benchmark:
Life Sciences
D. Explain the flow of energy and the cycling of matter through biological and
ecological systems (cellular, organismal and ecological).
Multiple Choice Question:
Use the information to answer questions 25 – 27.
Phytoplankton and Productivity
Phytoplankton are microscopic aquatic algae capable of photosynthesis.
The rate at which light energy is converted to organic compounds by the photosynthetic
organisms of an ecosystem is called productivity. Scientists have developed a method to
determine the productivity of phytoplankton in an aquatic habitat using the following steps.
Method to Determine Productivity
1. Two bottles, one transparent and one opaque, are filled with equal volumes of water
containing phytoplankton from the same depth of a lake.
2. Initial measurements of the concentrations of various dissolved gases for each bottle are
determined from a separate water sample taken from the same depth.
3. The two filled bottles are sealed and suspended in the water for 24 hours.
4. After 24 hours, the concentrations of various dissolved gases in each bottle are measured
and compared to the initial measurements of dissolved gases.
The diagram below shows the device used in the “Method to Determine Productivity.”
Source: Ohio Department of Education
August 07
Ohio Graduation Test for Science – March 2007
Annotated Item 26
26.
During the process of photosynthesis, phytoplankton convert the sun’s radiant energy into
which form of energy?
A.
B.
C.
D.
kinetic
chemical
electrical
mechanical
Commentary:
This multiple choice question asks students to identify the form of energy produced by
phytoplankton during photosynthesis. Students should recall that photosynthetic organisms
convert the sun’s radiant energy into glucose which is a product that stores chemical energy.
Answer choice B is correct because chemical energy results directly from photosynthesis.
Answer choice A is incorrect because photosynthesis does not directly produce kinetic energy.
Answer choices C and D incorrect because the process of photosynthesis does not produce
useable electrical or mechanical energy for the organism.
This question is classified as Recalling/Identifying Accurate Science because the task requires
students to correctly recall previously learned information about photosynthesis to identify the
type of energy produced in the process.
Performance Data:
The percent of public school students selecting answer choice B for question 26 on the March
2007 Ohio Graduation Test was 62%.
Keywords:
photosynthesis, chemical energy
Source: Ohio Department of Education
August 07