IC Lessons Photosynthesis and Respiration
This is lesson _1_ of _4_in this IC
A. Title of this lesson Floating Disks Questioning Strategies
B. Summary of this lesson
This Lesson 1 of the Photosynthesis and Respiration Unit allows the teacher to
gather Formative Assessment data (A Page Keeley probe) from the students in
order to proceed with the Unit. Other Formative Assessments can be gathered
by observing the students interacting with the leaves’ buoyancy. For the
students, it is a day of exploration with a variety of leaves and a tub of water.
The students explore a leaf’s property of buoyancy by experimenting with their
predictions on how to make a leaf sink. By allowing the students to suggest
techniques that will make the leaf sink and then have the students perform
those techniques on the leaves, will create learning.
For example, one student may suggest putting holes in the leaf; “Great, try it!”
Another may suggest tearing it; “Great, try it!”
Another yet may suggest to smash it into a ball; “Great, try it!”
After given an image of the cross section of a leaf, it is a goal that the students
will be able to engage in arguments using the evidence of the structure of a leaf
to predict what will occur when leaves are subjected to the vacuum created by
a syringe (needle removed).
A class discourse will occur as the students share their understanding and the
teacher is to take notes on this discussion to record any misconceptions.
C. Objective(s)/Learning Goal(s)/ Key Student Learning(s) of this lesson
1. A leaf’s structure affects its buoyancy.
2. A leaf’s structure allows an exchange in gases.
3. Removal of gases from a leaf allows it to sink.
D. Teacher Background Knowledge for this lesson
Created by Ariel Owen (Mt.Diablo USD), Linda Templeton (Alum Rock USD), Vina Sethi (Fremont USD), and
Denise Torrisi (Fremont USD)
IC Lessons Photosynthesis and Respiration
This is lesson _1_ of _4_in this IC
http://cerebralenhancementzone.wikispaces.com/Plants,+photosynthesis+and+food
Leaves have a buoyant property due to the gases, O2, CO2, and H2O (oxygen,
carbon dioxide, and water vapor) located in the spongy mesophyll. In order for
leaves to sink, as in the experiment in Lesson 2, the gases need to be removed
via a syringe. Therefore the knowledge of the structure of a leaf is important in
Created by Ariel Owen (Mt.Diablo USD), Linda Templeton (Alum Rock USD), Vina Sethi (Fremont USD), and
Denise Torrisi (Fremont USD)
IC Lessons Photosynthesis and Respiration
This is lesson _1_ of _4_in this IC
order for students to conceptualize what is occurring as they are pulling on the
syringe, see Photo 2.
Photo 2 Torrisi, D. Technique of removing gases from the leaf disks in Lesson 2
E. Prior knowledge that students need to understand this lesson - with an assessment to
determine what they already know (if appropriate).
1.
2.
3.
4.
Plants photosynthesize
Leaves are a living things
Leaves are composed of cells.
Living things have physical properties: mass, color, density/buoyancy, for
example.
F. Standards covered in this lesson
Current California Science Standards
7.1b. Students know the characteristics that distinguish plant cells from
animal cells, including chloroplasts and cell walls.
7.5a. Students know plants and animals have levels of organization for
structure and function, including cells, tissues, organs, organ systems, and
the whole organism.
7.6f. Students know light can be reflected, refracted, transmitted, and
absorbed by matter.
NGSS
Created by Ariel Owen (Mt.Diablo USD), Linda Templeton (Alum Rock USD), Vina Sethi (Fremont USD), and
Denise Torrisi (Fremont USD)
IC Lessons Photosynthesis and Respiration
This is lesson _1_ of _4_in this IC
8 Science Pratices:
3. Planning and Carrying Out Investigations
4. Analyzing and Interpreting Data
7. Engaging in Argument from Evidence
Crosscutting Concepts:
2. Cause and effect
CCSS
Reading: N/A
Writing:
7.1. Write arguments focused on discipline-specific content.
a. Introduce claim(s) about a topic or issue, acknowledge and distinguish
the claim(s) from alternate or opposing claims, and organize the reasons
and evidence logically.
e. Provide a concluding statement or section that follows from and
supports the argument presented.
Listening & Speaking:
7.1 Engage effectively in a range of collaborative discussions (one-onone, in groups, and teacher-led) with diverse partners on grade 7 topics,
texts,…)
7.1c Pose questions that elicit elaboration and respond to other’s
questions and comments with relevant observations…)
7.4 Present claims and findings, emphasizing salient points in a focused,
coherent manner
With pertinent descriptions, facts, details, examples…)
Math: N/A
Created by Ariel Owen (Mt.Diablo USD), Linda Templeton (Alum Rock USD), Vina Sethi (Fremont USD), and
Denise Torrisi (Fremont USD)
IC Lessons Photosynthesis and Respiration
This is lesson _1_ of _4_in this IC
G. Suggested time to complete this lesson
50 minutes
H. Materials Used in this lesson typed in a bulleted list with quantities (e.g., 10 beakers; water of
2 liters)
 1 Floating Leaf Lesson 1 worksheet per student
 1 leaf per student (May assign homework the night before to have each
student to bring a leaf)
 1 tub per group shoe box size would be fine.
 Access to water for students to experiment with the leaves’ property of
buoyancy.
Photo 1: Torrisi, D.(Example of students experimenting with the buoyancy of
leaves)
 1 per group: hand held hole punch
 Resource for students to write: Lab Notebooks or paper
I. Materials Prep for this lesson (should include number of copies needed (e.g. one probe per
student, one set of directions per lab group)
 1 per student: A print out of Page Keeley’s Probe “Uncovering Student
Ideas in Life Science –
Life Processes and Needs of Living Needs of Living Things Light and Dark
(pg 63)
 Have 1 tub per group and four leaves per group of four, IF a homework
assignment was NOT given to the students for each of them to bring a
leaf into class.
Created by Ariel Owen (Mt.Diablo USD), Linda Templeton (Alum Rock USD), Vina Sethi (Fremont USD), and
Denise Torrisi (Fremont USD)
IC Lessons Photosynthesis and Respiration
This is lesson _1_ of _4_in this IC
 Copy 1 image per 2 students of: Storyboard E (Cross Section of a leaf)
(these images will also be used during Lesson 3, Storyboard), laminate to
make a class set.
J. Lesson Plan – detailed, numbered step-by-step plans.
1. Either the day/s before this Unit or the same day, have students complete
pg 63 Page Keeley’s Probe “Uncovering Student Ideas in Life Science – Life
Processes and Needs of Living Needs of Living Things Light and Dark (pg 6368)
2. Have 1 tub per group and four leaves per group of four, IF a homework
assignment was NOT given to the students for each of them to bring a leaf
into class, out on each group table.
3. Have a laminated copy, 1 per 2 students, of: Image 1-Storyboard E (Cross
Section of a leaf) out on each group table along with a hand held hole
punch.
4. Pass out student worksheet, Floating Disks Lesson 1 to each student.
5. Have the students complete questions 1 and 2 on the worksheet. They will
need the copy of Image 1-Storyboard E (Cross Section of a leaf) to complete
question 2.
6. Have students complete question 3… then they are to place their leaves in
the tub of water. Have them record their results, question 4.
7. BEFORE they complete question 5, try to get a class discussion going using
the following prompts:
a. How could you get the leaves to sink?
b. Stress that the leaves can’t be weighted down. They must sink on
their own.
c. What about a leaf’s structure would allow it to float? Sink? Look at
BOX 2
Created by Ariel Owen (Mt.Diablo USD), Linda Templeton (Alum Rock USD), Vina Sethi (Fremont USD), and
Denise Torrisi (Fremont USD)
IC Lessons Photosynthesis and Respiration
This is lesson _1_ of _4_in this IC
d. What types of gases are located in the spongy mesophyll?
e. How do the gases enter and leave the leaf?
f. Do the gases in the leaves have anything to do with the leaves
floating?
g. What would happen to the leaf if some of the gases were removed?
h. What would happen to the leaf if some gases were added?
8. Ask them to complete question 5. They can use the hole punch that is
provided for each group, however it is best not to mention it. Have the
students find in and ask if it is available to them, therefore they are in
charge of their own learning. The hole punch will be used again in Lesson 2
to create leaf disks; the teacher is gently guiding the students in order to
help them conceptualize what is actually occurring when they complete the
techniques in Lesson 2. Ultimately, the disks will be photosynthesizing
under light with a source of carbon from sodium bicarbonate.
9. Ask students “If you were given a syringe (yes clean, needle removed) how
might you get the leaves to sink?”
10. Have students discuss this idea with their lab group. They are to write and
draw their predictions and techniques under question 6. They are also to
select 1 or 2 people from their group to share the ideas with the class.
11. Have a class discourse; the students share their understanding and
predictions or techniques that they came up with, as a group. Have 1-2
people from the group to share, with the class, the ideas of how they could
make the leaves sink by using a syringe. During the discussion they are to
use evidence based on their explorations with the buoyancy of leaves and
their knowledge of the structure of a cross section of a leaf.
Created by Ariel Owen (Mt.Diablo USD), Linda Templeton (Alum Rock USD), Vina Sethi (Fremont USD), and
Denise Torrisi (Fremont USD)
IC Lessons Photosynthesis and Respiration
This is lesson _1_ of _4_in this IC
12. The teacher is to take notes on this discussion to record any misconceptions.
Any misconceptions based on this discussion or from Keeley’s Light and Dark
probe can be covered throughout the unit.
K. Vocabulary words – key vocabulary words that are targeted or taught as part of the lesson.
Gases, CO2 (carbon dioxide), O2 (oxygen), H2O(g) (water vapor), stoma and stomata,
guard cell, spongy mesophyll, cuticle, epidermis, and vacuum
L. Potential Pitfalls for: a. student understanding; b. laboratory mishaps and common procedural
errors; c. academic vocabulary issues, etc.
Good classroom management skills are necessary when dealing with leaves and tubs of
water.
Splashing of water is never allowed.
Students need to clean up their lab stations or tables before the next class.
M.Differentiation: Modifications for English Learners, advanced learners, struggling learners, etc.
English Learners may be allowed to draw only if writing is not their strength and correct
spelling is not a necessity.
N. Please list all worksheets used in this lesson.
Floating Leaf Lesson 1 worksheet
O. Please list all assessments that require a separate sheet.
N/A
P. Photos/Illustrations
Storyboard E for Floating Disks Questioning Strategies and Lesson 3 (see
attached)
Created by Ariel Owen (Mt.Diablo USD), Linda Templeton (Alum Rock USD), Vina Sethi (Fremont USD), and
Denise Torrisi (Fremont USD)
IC Lessons Photosynthesis and Respiration
Q.
This is lesson _1_ of _4_in this IC
Other Resources
N/A
Name__________________________________________
Date _________________ Period ________
Floating Disks Lesson 1
1.
Draw an image of your leaf in BOX 1. 2. Draw and label a cross section of a leaf in BOX 2
BOX 1
BOX 2
3. Do you think your leaf will float or sink? ________________
4. Try it! Put your leaf in the tub of water. What happened?
______________________________________________________________________________
5. After talking with your lab group, list 3 ideas or ways the group came up, to make the leaves sink!
Try the ideas. What happened? Record the ideas and your results in the table below.
Ideas
Results - What happened?
1.
2.
3.
6. If you were given a syringe (yes clean, needle removed) how might you get the leaves to sink?
Discuss this with your lab group. Write and draw your predictions or techniques in the space
below. Use evidence from explorations with the leaves and BOX 2.
Created by Ariel Owen (Mt.Diablo USD), Linda Templeton (Alum Rock USD), Vina Sethi (Fremont USD), and
Denise Torrisi (Fremont USD)
IC Lessons Photosynthesis and Respiration
This is lesson _1_ of _4_in this IC
Image 1 - Storyboard E for Floating Disks Questioning Strategies and Lesson 3
Image 1
Image 1
http://www.goldiesroom.org/Note%20Packets/05%20Nutrition/04%20Nutrition--Lesson%204.htm
Created by Ariel Owen (Mt.Diablo USD), Linda Templeton (Alum Rock USD), Vina Sethi (Fremont USD), and
Denise Torrisi (Fremont USD)