Transcript Assessment - What Evidence do You Accept?

Key Concept: Carbon Cycle
Goals: Students will be able to …
Trace the pathway of a carbon atom through
living and nonliving components of an
ecosystem, explaining both the processes and
types of organisms involved.
Carbon Cycle Pre-test
Pre-test
Which of the following substances has mass?
Answer yes or no in the blank to the left.
H20 vapor _______
CO2 _______
Glucose (C6H12O6) _______
O2 _______
Student Responses
(n=171)
Pre-test
What are the different pathways that carbon can
take once it is inside a plant? select as many as apply
a.
b.
c.
d.
it can exit the plant as CO2
it can become part of the plant’s cell walls, protein, fat,
DNA
it can be consumed by an insect feeding on the plant and
become part of the insect’s body
as a plant decomposes in the soil, carbon can exit the soil
as CO2
Student Responses
(n=171)
Pre-test
The majority of the actual weight (dry biomass) gained by
plants as they progress from seed to adult plant comes from
which of the following substances?
a.
b.
c.
d.
molecules in the air that enter through the leaves
particle substances in the soil taken up by the roots
substances dissolved in water that are taken up by roots
energy from the sun
Student Responses
(n=171)
Instructional Design


Lecture: food chains and webs (15 min)
Lecture: energy flow / matter cycling (80 min)
» Matter / conservation of matter
» Energy / types of energy
» Laws of thermodynamics
» Efficiency of energy transfer
» Biogeochemical Cycles- biological & geological forms
and processes
Formative Assessment


Explain this statement: Energy flows through an
ecosystem. Matter cycles within an ecosystem.
Discuss in your group - submit one answer per
group.
In-class Group Activity
1.
2.
3.
4.
Draw a food chain based on the diagram of the carbon
cycle in Figure 3-16. Include the decomposers. Label
each trophic level.
Incoming radiation from the sun is 1,7000,000 kcals.
Based on how energy flows through ecosystems,
calculate the amount of kcals available for each trophic
level.
On the diagram, show how and in what form (use
arrows) energy is lost from each trophic level.
On the diagram, indicate in what form carbon moves
into and out of each trophic level and the biological
process that enables carbon movement to occur.
Radish Experiment



Experimental Setup:
Weighed out 3 batches of radish seeds each weighing 1.5 g.
Experimental treatments:
» 1. Seeds placed on moistened paper towels in LIGHT
» 2. Seeds placed on moistened paper
towels in DARK
» 3. Seeds not moistened (left DRY) placed in light
Radish Experiment

In-class group activity:
1. Develop a testable hypothesis for your group’s
experiment.
2. Define the dependent and independent variables in
your hypothesis.
3. Design a method to measure primary productivity
for your experiment.
4. Predict the results.
Radish Experiment

After 2 weeks, all plant material was dried in an
oven overnight (no water left) and plant biomass
was measured in grams.
Processing Radish Experiment
(week 7)
1.46 g
1.63 g
1.20 g
Formative Assessment: Write an explanation of
the results.
The Grandma Johnson Problem
Hypothetical Scenario: Grandma Johnson had very
sentimental feelings toward Johnson Canyon, Utah where she
and her late husband had honeymooned long ago. Her feelings
toward this spot were such that upon her death she
requested to be buried under a creosote bush overlooking the
canyon. She loved the idea that she'd become part of the
wonderful wilderness and live on through the wildlife that
lived there. Think to yourself and begin to trace the path of a
carbon atom from Grandma Johnson's (GJ) remains to where
it could become part of a coyote (NOTE: the coyote WILL
NOT dig up Grandma and consume any of her remains). What
fundamental pathways and processes of biology will be
involved in the transit of GJ's carbon atoms to that of the
wild coyote in Utah?
Task: Create a concept map that illustrates your understanding of the
relationship between these 10 concepts in the context of the Grandma
Johnson problem. You may add up to 5 extra concepts if you need them to
explain the problem more clearly.
photosynthesis
respiration
carbon cycle
decomposers
primary producers
consumers
carbon dioxide
glucose
energy
oxygen
1. Work on the problem individually first, save it in CTOOLS, and print a hard
copy.
2. Work on the problem with a partner. Both of you can retrieve your concept
maps, discuss, revise and produce the best final map to which both of you have
contributed.
3. Submit all three maps - yours, your partner's and the FINAL MAP you
completed together - Please put the final map on top, with both of your names.
Staple them together (5 pts off if not stapled).
Summative Assessments



Analogous questions from pre-test
The final exam was optional; 72 of 182
students chose not to take the final
The following data are from the 110
who took the final
Summative Assessment
(final exam)
Which of the following substances has mass?
Answer yes or no in the blank to the left.
H20 vapor _______
CO2 _______
Glucose (C6H12O6) _______
O2 _______
Student Responses
(n=110)
Summative Assessment
(final exam)
What are the different pathways that carbon can
take once it is inside a plant?
a.
b.
c.
d.
it can exit the plant as CO2
it can become part of the plant’s cell walls, protein, fat,
DNA
it can be consumed by an insect feeding on the plant and
become part of the insect’s body
as a plant decomposes in the soil, carbon can exit the soil
as CO2
Student Responses
(n=171)
Summative Assessment
(final exam)
The majority of the actual weight (dry biomass) gained by
plants as they progress from seed to adult plant comes from
which of the following substances?
a.
b.
c.
d.
molecules in the air that enter through the leaves
particle substances in the soil taken up by the roots
substances dissolved in water that are taken up by roots
energy from the sun
Student Responses
(n=171)
Success!!

Students understand the carbon cycle.
Really??
Appropriate Assessment

Three questions on the final exam
assessed student understanding of the
concept that plants get carbon from
CO2 in the atmosphere.
Multiple Choice
The majority of the actual weight (dry biomass) gained by
plants as they progress from seed to adult plant comes from
which of the following substances?
a.
b.
c.
d.
molecules in the air that enter through the leaves
particle substances in the soil taken up by the roots
substances dissolved in water that are taken up by
roots
energy from the sun
Fill-in table
Spider Monkey Problem
Written response: Explain in detail the following:
Deep within a remote forest of Guatemala, the remains of a spider
monkey were buried under an enormous mahogany tree. Although
rare, jaguars have been spotted in this forest by local farmers. Use
coherently written sentences and clearly labeled drawings to explain
how a carbon atom in glucose contained within the muscle cells of the
spider monkey might become part of a cell within the stomach lining
of a jaguar. Provide a written description of the processes AND
organisms the carbon atom must go through to cycle through the
ecosystem. Include a clearly labeled drawing of the system. (Note:
the jaguar does not dig up the monkey and eat the remains!)
Where do plants get carbon?
(final exam)