7th Grade/Life Science
Ecosystems
All living things are dependent on each other.
Enduring Understanding Organisms adapt to live in different environments.
Organisms respond to changes in their environments.
LS.5 The student will investigate and understand the basic
physical and chemical processes of photosynthesis
and its importance to plant and animal life. Key
concepts include
a) energy transfer between sunlight and
chlorophyll;
b) transformation of water and carbon dioxide
into sugar and oxygen; and
c) photosynthesis as the foundation of
virtually all food webs.
LS.6 The student will investigate and understand that
organisms within an ecosystem are dependent on one
another and on nonliving components of the
environment. Key concepts include
a) the carbon, water, and nitrogen cycles;
b) interactions resulting in a flow of energy and
matter throughout the system;
c) complex relationships within terrestrial,
freshwater, and marine ecosystems; and
d) energy flow in food webs and energy
pyramids.
SOL Objectives
LS.7 The student will investigate and understand that
interactions exist among members of a population.
Key concepts include
a) competition, cooperation, social hierarchy,
territorial imperative; and
b) influence of behavior on a population.
LS.7 The student will investigate and understand that
interactions exist among members of a population.
Key concepts include
a) competition, cooperation, social hierarchy,
territorial imperative; and
b) influence of behavior on a population.
LS.8 The student will investigate and understand
interactions among populations in a biological
community. Key concepts include
a) the relationships among producers,
consumers, and decomposers in food webs;
b) the relationship between predators and prey;
c) competition and cooperation;
d) symbiotic relationships; and niches.
What am I Breathing?
Title
Students will see the release of CO2 from respiration to
realize the release of O2 from photosynthesis. They will
Lesson Objective
then use that knowledge to design an experiment to observe
Grade Level/Subject
Unit
Inquiry Level
Materials Needed
How is it Level 3?
the exchange between photosynthesis and respiration.
3
Student Lab Sheet
Bromothymol Blue
Straw
Water
Aquatic plant (Elodea or any plant sold for fish tanks)
Bean seeds
Beakers
The teacher provides the initial question and procedures to
describe the phenomenon, but the students design the final
procedures and analyze the outcome of the results.
Name __________________________________________________________________________________________________
Respiration and Photosynthesis
IV: ____________________________________________________________________
(What organisms are you comparing? What is different about those organisms?)
DV: ___________________________________________________________________
(How are you measuring that action?)
Problem: _______________________________________________________________
_______________________________________________________________
Hypothesis: _____________________________________________________________
_____________________________________________________________
Procedures:
Materials: 1 beaker
1 graduated cylinder
a few drops of Bromothymol Blue (an indicator that shows the
presence CO2 in water)
1 plastic straw
200 mL of water
1 Elodea sprig
Procedures:
1. Fill the beaker with 100 mL of water, using the graduated cylinder to
measure the water from the tap in the sink.
2. Use the dropper in the Bromothymol Blue to drop 10 drops into the
beaker. This should turn the water blue.
3. Place the plastic straw into the water, and one person in the group will
blow into the straw (like a little kid blowing bubbles in their drink). Do
not blow so hard the bubbles come over the side of the beaker.
4. Record what happens to the water/Bromothymol Blue solution.
5. Prepare a wet mount of Elodea, with the bottom facing up. Look for the
structures on the bottom side of the leaf that would help the leaf during
Photosynthesis.
6. Place 3 drops of Bromothymol Blue on one side of the coverslip and draw
the stain under the coverslip.
7. Observe what occurs to the Bromothymol Blue solution and record the
data.
8. Use the data to design a experiment to show the exchange of CO2 and O2
using any of the materials (Bromothymol Blue, water, Elodea, or a bean).
Analyze your results and explain how the experiment shows the exchange
of gases.
1/2
Data:
Draw a picture of the change in the Bromothymol Blue Solution when blown into
through a straw. Then write a description of the change.
Initial
10 seconds
30 seconds
45 seconds
60 seconds
Observations of the Elodea leaf in Bromothymol Blue.
Analysis: Answer each question in complete sentences, as thoroughly as possible.
1. Why would the Bromothymol Blue solution change color when a person blows
into the solution?
2. How do the structures visible on the Elodea slide assist plants with
photosynthesis?
3. What is happening when the bromothymol blue solution is near the elodea leaf?
4. How does the change in Bromothymol Blue solution being blown into relate the
change in the solution surrounding the Elodea leaf?
5. Look back at your Problem and Hypothesis. How did the experiment relate to
your original Problem and Hypothesis?
Conclusion: Complete the picture relating photosynthesis and respiration. Add in the
equations for each process.
Design Your Own CO2/O2 Experiment
PROBLEM: ____________________________________________________________
____________________________________________________________
IV: ___________________________________________________________________
DV: __________________________________________________________________
HYPOTHESIS: __________________________________________________________
__________________________________________________________
__________________________________________________________
PROCEDURES:
1. _____________________________________________________________________
_____________________________________________________________________
2. _____________________________________________________________________
_____________________________________________________________________
3. _____________________________________________________________________
_____________________________________________________________________
4. _____________________________________________________________________
_____________________________________________________________________
5. _____________________________________________________________________
_____________________________________________________________________
6. _____________________________________________________________________
_____________________________________________________________________
7. _____________________________________________________________________
_____________________________________________________________________
8. _____________________________________________________________________
_____________________________________________________________________
9. _____________________________________________________________________
_____________________________________________________________________
10. _____________________________________________________________________
_____________________________________________________________________
DATA:
ANALYSIS:
CONCLUSION:
Name __________________________________________________________________________________________________
Respiration and Photosynthesis
IV: ____________________________________________________________________
(What organisms are you comparing? What is different about those organisms?)
DV: ___________________________________________________________________
(How are you measuring that action?)
Problem: _______________________________________________________________
_______________________________________________________________
Hypothesis: _____________________________________________________________
_____________________________________________________________
Procedures:
Materials: 1 beaker
1 graduated cylinder
a few drops of Bromothymol Blue (an indicator that shows the
presence CO2 in water)
1 plastic straw
200 mL of water
1 Elodea sprig
Procedures:
1. Fill the beaker with 100 mL of water, using the graduated cylinder to
measure the water from the tap in the sink.
2. Use the dropper in the Bromothymol Blue to drop 10 drops into the
beaker. This should turn the water blue.
3. Place the plastic straw into the water, and one person in the group will
blow into the straw (like a little kid blowing bubbles in their drink). Do
not blow so hard the bubbles come over the side of the beaker.
4. Record what happens to the water/Bromothymol Blue solution.
5. Prepare a wet mount of Elodea, with the bottom facing up. Look for the
structures on the bottom side of the leaf that would help the leaf during
Photosynthesis.
6. Place 3 drops of Bromothymol Blue on one side of the coverslip and draw
the stain under the coverslip.
7. Observe what occurs to the Bromothymol Blue solution and record the
data.
8. Use the data to design a experiment to show the exchange of CO2 and O2
using any of the materials (Bromothymol Blue, water, Elodea, or a bean).
Analyze your results and explain how the experiment shows the exchange
of gases.
3/4
Data:
Draw a picture of the change in the Bromothymol Blue Solution when blown into
through a straw. Then write a description of the change.
Initial
10 seconds
30 seconds
45 seconds
60 seconds
Observations of the Elodea leaf in Bromothymol Blue.
Analysis: Answer each question in complete sentences, as thoroughly as possible.
1. Identify why the bromothymol blue resulted in changing color when someone
blew into it.
2. Explain how the structures visible on the Elodea slide assist plants with
photosynthesis.
3. Predict what occurred in the bromothymol blue solution near the elodea leaf.
4. What is the relationship between the Bromothymol Blue solution being blown
into and the solution surrounding the Elodea leaf?
5. Look back at your Problem and Hypothesis. Were your problem and hypothesis
relevant? Explain.
Conclusion: Complete A picture relating photosynthesis and respiration. Use the
equations for each process. The picture should include a plant and a
person.
Name __________________________________________________________________________________________________
Respiration and Photosynthesis
IV: ____________________________________________________________________
(What organisms are you comparing? What is different about those organisms?)
DV: ___________________________________________________________________
(How are you measuring that action?)
Problem: _______________________________________________________________
_______________________________________________________________
Hypothesis: _____________________________________________________________
_____________________________________________________________
Procedures:
Materials: 1 beaker
1 graduated cylinder
a few drops of Bromothymol Blue (an indicator that shows the
presence CO2 in water)
1 plastic straw
200 mL of water
1 Elodea sprig
Procedures:
1. Fill the beaker with 100 mL of water, using the graduated cylinder to
measure the water from the tap in the sink.
2. Use the dropper in the Bromothymol Blue to drop 10 drops into the
beaker. This should turn the water blue.
3. Place the plastic straw into the water, and one person in the group will
blow into the straw (like a little kid blowing bubbles in their drink). Do
not blow so hard the bubbles come over the side of the beaker.
4. Record what happens to the water/Bromothymol Blue solution.
5. Prepare a wet mount of Elodea, with the bottom facing up. Look for the
structures on the bottom side of the leaf that would help the leaf during
Photosynthesis.
6. Place 3 drops of Bromothymol Blue on one side of the coverslip and draw
the stain under the coverslip.
7. Observe what occurs to the Bromothymol Blue solution and record the
data.
8. Use the data to design a experiment to show the exchange of CO2 and O2
using any of the materials (Bromothymol Blue, water, Elodea, or a bean).
Analyze your results and explain how the experiment shows the exchange
of gases.
5/6
Data:
Draw a picture of the change in the Bromothymol Blue Solution when blown into
through a straw. Then write a description of the change.
Initial
10 seconds
30 seconds
45 seconds
60 seconds
Observations of the Elodea leaf in Bromothymol Blue.
Analysis: Answer each question in complete sentences, as thoroughly as possible.
1. Develop and explanation of why the bromothymol blue resulted in changing color
when someone blew into it.
2. Explain how the structures visible on the Elodea slide are consistent in all plants,
and how those structures relate to photosynthesis.
3. State an explanation of what occurred in the bromothymol blue solution near the
elodea leaf.
4. Compare the bromothymol blue solution being blown into versus the solution
surrounding the elodea leaf.
5. Look back at your Problem and Hypothesis. Criticize or defend your problem and
hypothesis.
Conclusion: Create A picture relating photosynthesis and respiration. Use the equations
for each process.