Part Six – Section B
Lesson Plan for Problem Solving Unit
Rocky Run Middle School
This lesson plan is based on the LEARN model and contains all of the appropriate requirements.
Link
SOL/POS/Objectives:
LS.1 F The student will identify the key components of a controlled experiment.
1. Identify the key components of a controlled experiment: hypothesis, independent and dependent variables, constants, control, and repeated
trials.
The independent (manipulated) variable is deliberately changed in the experiment and the dependent (responding) variable is measured.
Constants are the variables in an experiment which must not change in order for the investigation to represent a fair test.
2. Distinguish between observational and experimental investigations.
LS.1 G The student will manipulate the key components of a controlled experiment.
1. Design and conduct scientific investigations to test a hypothesis to obtain reliable data by applying the generalized steps of experimental
methodology (formerly FCPS Standard 4).
a. State the problem or question.
b. Formulate hypotheses based on evidence that can be tested through experimentation.
c. Make predictions based on prior knowledge, understandings, observations and inferences.
d. Develop and follow a clear and logical procedure to test a hypothesis.
e. Identify and control variables to investigate the outcome of an event while other factors are held constant.
f. Use the senses to make qualitative and/or quantitative observations to gather and record information about observations and measurements in a
systematic way.
LS.1 I The student will formulate valid conclusions after analyzing data and observations.
1. Formulate conclusions that are supported by the gathered data.
a. Make inferences, predictions, or interpretations.
b. Recognize cause and effect relationships.
c. Determine patterns, trends, and relationships in data.
d. Develop/support explanations, hypotheses, and models based on evidence.
LS.4 B The student will investigate and understand the basic needs and life processes of animals.
1. Identify the needs of animals and how they obtain the resources to meet those needs to carry out life processes.
a. Recognize that animals carry out the process of cellular respiration.
Animals must consume other organisms to obtain energy (food) and other nutrients to carry out life processes.
Most animals obtain oxygen for cellular respiration from their environment.
2. Distinguish between the needs of plants and animals.
LS.6 B The student will investigate and understand the basic physical and chemical processes of cellular respiration and its importance
to plant and animal life.
1. Use words or chemical equations to compare and contrast the processes of photosynthesis and respiration in terms of raw materials required,
products produced, and cellular organelles involved.
2. Recognize that the products of photosynthesis are used by both plants and animals.
Cellular respiration is the process whereby all organisms obtain energy.
Animals eat plants to obtain stored sugars and other molecules which are the raw materials necessary for movement, growth, repair, development,
and reproduction.
LS 7 A The students will investigate and understand the carbon, nitrogen, and water cycles.
2. Differentiate among key processes in the carbon cycle and analyze how organisms (from bacteria and fungi to third level consumers) function
to recycle matter in an ecosystem.
a. Recognize that the carbon dioxide – oxygen cycle (photosynthesis and cellular respiration) is part of the carbon cycle.
Engage
Problem Engagement:
1. Read and discuss with the class the introductory paragraph at the top of the “Indicators of
Respiration” lab.
2. Engage students in a brief discussion about how they might go about determining the answer
to the questions posed in the introductory paragraph.
Active
Inquiry Investigation:
1. Have students answer the “Before You Begin” questions. Use the “Think-Pair-Share”
strategy.
2. Discuss with students how scientists can use “indicators” to help them tell whether chemicals
are present that they cannot see. Explain how people test the water of a swimming pool as an
example.
3. Introduce Bromothymol Blue (BTB) as an indicator. Read through Question 1 of “Part One:
What is BTB?” And have students discuss as a group their thoughts about the answer to
question one. Applying their prior knowledge of the pH scale, students should be able to
conclude that the addition of carbon dioxide to water (such as happens when acid rain is formed,)
will make the water more acidic, and therefore change the color of the BTB and water solution.
4. Confirm the students’ predictions with a demonstration of how BTB works: Pour water into
4-6 plastic cups, and add several drops of BTB to each cup. Place a straw in each cup. Pass out
the cups with straws to student volunteers, and instruct the volunteers to stand in strategic places
around the room that allow all of the students in the class to be able to see the cups. Ask the
student volunteers to blow air through the straws into the BTB-water solution in the cup. The
solution should turn from blue to yellow with the addition of CO2.
5. Have students answer Question 2 of “Part One: What is BTB?” Using “Think-Pair-Share.”
Devising a Plan:
1. Bring students back to the original experiment questions, written in the text box in Step 1 of
“Part Two: Plan an Experiment.”
2. Explain that you would like all of the students to use the same materials, and introduce
students to the materials they will have available, as listed in Step 2 of “Part Two: Plan an
Experiment.” Make sure students are aware that pond snails have gills and are therefore capable
of breathing underwater, and that elodea plants are also typically found submerged underwater.
3. Have students work in groups to devise an experiment which will answer the problem
questions. Students should follow the directions in Steps 3, 4, and 5 of “Part Two: Plan an
Experiment.”
4. Have each group present their procedure steps, drawing, and data table to the class. Discuss
as a class the merits of each plan. Be sure to emphasize the following:
 The importance of separating the plant and the animal in different vials, so that only one
variable is tested at a time.
 The importance of having vials that contain only BTB and water and no plant or animal
as a control, to make sure that there is no other factor causing the BTB to change color.
5. With your guidance, have the class choose the best set of procedures to follow to set up the
experiment. The class may choose one group’s idea entirely, or combine ideas from several
groups. The class should also choose the best data table to use.
6. Have students write one or more hypotheses predicting the results of the experiment, as
instructed in the section, “Part Three: Hypothesis.”
Carrying Out the Plan:
1. The experiment can be conducted separately by each group, or as a whole class, depending on
the availability of materials.
2. Students should draw a color picture of how the experiment is set up, using the template given
in “Part Four: Experiment Set Up.”
3. It will take 24 hours for the BTB in the vials to change color.
4. At the beginning of the next class period, students should fill in the data table and complete
the drawings in the section, “Part Five: Observations.”
Reflection
Reflect:
1. Use “Think-Pair-Share” to have students complete the questions in “Part Six: Analysis,” and “Part Seven:
Application.”
2. Discuss with students the interdependence of plants and animals as illustrated in the carbon dioxide-oxygen
cycle. Discuss with the class the following questions:
 Can animals survive on earth without plants? Why or why not?
 Can plants survive without animals? Why or why not?
Next
Tomorrow:
Preview the next lesson:
Now that students understand how living things need basic materials like water, oxygen, and
carbon dioxide, in the next lab we will look at how these materials go in and out of cells through
the processes of osmosis, diffusion, and active transport.
Indicators of Respiration
You have learned that plants are able to make their own food through the process of
photosynthesis. You also know that animals depend upon plants for their food either directly or
indirectly. The food is also a source of stored energy which must be released so that it can be
used for all life processes. The process which releases the energy from food within all cells is
called respiration. Do plants carry on respiration? Does respiration require light as
photosynthesis does? Let’s find out!
Before you Begin: What do you already know?
1. What gas does your body take from the air to use in the process of respiration?
2. What gas is produced as a waste product of respiration, which you exhale?
Part One: What is BTB?
1. Bromothymol Blue (BTB) is a chemical indicator of acids and bases. It works by
changing color in slightly acidic or slightly basic solutions. Brainstorm how you think
BTB works. What do you think you could add to a solution of water and BTB that
would make the BTB change color?
2. After watching the demonstration of BTB, how can BTB be used to indicate whether
respiration has occurred?
Part Two: Plan an Experiment
1. With your group, consider the following questions:
Does respiration occur in both plants and animals?
Does respiration occur at all times, or only during the day (like
photosynthesis), or only at night?
2. Consider that you have the following materials available:
Elodea plants
Pond snails
Aquarium water
BTB
Cylindrical vials with lids to contain organisms
Light cart to simulate daytime conditions
Dark cabinet to simulate nighttime conditions
3. As a group, write a set of procedures that will answer the two questions above on a separate
sheet of paper.
4. As a group, draw a picture of how the experiment would be set up on a separate sheet of
paper.
5. As a group, create a Data Table on a separate sheet of paper that could be used to record your
results.
6. Your class will decide together on the best set of procedures and Data Table to use.
Part Three: Hypothesis
Write one or more hypotheses in the space below indicating what you predict the results of the
experiment will show. Be sure your hypotheses addresses all of the questions listed in the box
above.
Part Four: Experiment Set Up
As the experiment is set up, draw a picture of what is put in each vial.
Vials in the Light
A
B
C
Vials in the Dark
D
E
F
G
H
Part Five: Observations
After the experiment is completed, draw a picture of what was put in each vial, AND what the
final color of the BTB solution in the vial was.
Vials in the Light
A
B
C
Vials in the Dark
D
E
F
G
H
Part Five: Observations
Copy the Data Table that your class has decided to use in the space below and record your
results.
Part Six: Analysis
Using the data and observations from this experiment, answer the following questions:
Does respiration occur in both plants and animals?
Does respiration occur at all times, or only during the day (like
photosynthesis), or only at night?
Part Seven: Application
Use the diagram below to demonstrate what you have learned about how plants and animals
exchange gases during photosynthesis and respiration.