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Relating Structure to Function in Cells – Grade 12

Ohio Standards Lesson Summary:
Connection: In this lesson, students will investigate specialized
Life Sciences
structures in both plants and animals. They will relate
structure to function, as they determine why the
Benchmark A specialization is necessary and useful to the living
Explain how processes at organisms involved. They will use microscopes to look at
the cellular level affect the cells and they will investigate the differences between
functions and
characteristics of an
different types of cells.
organism.
Estimated Duration: Four hours
Indicator 2
Explain why specialized
cells/structures are useful Commentary:
to plants and animals (e.g.,
This lesson addresses the basics of cell structure and
stoma, phloem, xylem,
blood, nerve, muscle, egg function. Students are able to view a variety of cells and
and sperm.) evaluate why the structure of the cell exists, in relation to
the function that it must perform. One teacher in the field
reviewed this lesson and commented: “It is very adaptable
to various skill/grade levels of students. It could be
modified for advanced level students, as well as for those
still struggling to master the basic knowledge of the
standard.”

Pre-Assessment:
Write the following questions on the board. Instruct students
to answer the questions on a sheet of paper.
1. What makes blood cells different from nerve cells?
2. What is meant by cell specialization?
3. Give an example of a specialized cell and explain its
purpose.
4. Why do we need different types of cells in order to
maintain homeostasis?

Scoring Guidelines:
1. What makes blood cells different from nerve cells?
Blood cells are specialized for carrying oxygen or fighting
disease, while nerve cells conduct nerve impulses from the
body, to the brain, and back to the body
2. What is meant by cell specialization?
Cell specialization is the design of cells of an organism
specifically for a certain function.

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Relating Structure to Function in Cells – Grade 12
3. Give an example of a specialized cell and explain its purpose.
White blood cells – fight disease; red blood cells – carry oxygen to the body;
cnidocysts – for defense in cnidarians, contain nematocyst, a stinging cell.
4. Why do we need different types of cells in order to maintain homeostasis?
Different cells perform different functions. Success of these functions is crucial for
maintenance of homeostasis.

Use the pre-assessment as an indicator of student prior knowledge on the indicator and a
guide for instruction. It can be a springboard for class discussion.

Post-Assessment:
Have students examine several examples of different types of cells and explain how the
structure of each cell relates to its function. Distribute Attachment A, Post-Assessment to
provide guidelines for this assessment.

Scoring Guidelines:
Use Attachment B, Post-Assesment Scoring Guidelines to assess student work.

Instructional Procedures:
Part One - Introduction
1. Discuss responses to the pre-assessment questions with students. This can be a whole
class discussion, think-pair-share, or other method of generating conversation about
the topic with the students.
2. Explain to students that many cells have special structures for certain functions.
Give the students examples from both the plant and animal kingdom.

Instructional Tip:
Some examples include: xylem and phloem cells in plants, stoma in plants; blood cells,
muscle cells, and various other types of cells in animals, such as villi and microvilli in the
stomach (to increase the surface area and enhance absorption). Stress the importance of
structure and function in these specialized structures.

Part Two – Mosses vs. Vascular Plants
3. Provide students with examples of mosses and vascular plants. Have them make a T-
chart listing the observable characteristics of both mosses and vascular plants. See
Attachment C, T-Chart.

Instructional Tip:
Make an overhead of the T-chart. With the class, compare and contrast mosses and
vascular plants. Work across, writing one statement for mosses, and then a comparison or
contrasting statement for vascular plants.

4. Define vascular tissue, xylem, and phloem for students. Review diffusion and
osmosis.

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Relating Structure to Function in Cells – Grade 12
5. Have students use the microscope to look at cross-sections of vascular plants. Have
students draw a diagram of their slide and identify the xylem and the phloem on the
slide.

Instructional Tip:
Use prepared slides, or have students make their own slide with a VERY thin section of
stem from a plant such as a Swedish Ivy.

6. Have students look at a cross-section of moss under the microscope and draw it.
Have students compare Swedish Ivy and moss. Students should observe and note that
there is no xylem or phloem on the slide of moss.
7. Ask students, “How do you think mosses transport food and water if they have no
vascular tissue?” Have students share their answers with the class.
8. Explain to students that the size of the moss is directly related to the fact that they
don’t have vascular tissue. They should understand that mosses must be small,
because they are unable to transport water great distances.

Part Three – Stomata
Instructional Tip:
A leafy plant such as leaf lettuce works well for this activity.

9. Provide students with a copy of Attachment D, Observing Stomata. Have students
research the function of stomata in plant cells.
10. Using a leaf, have students “snap” the leaf in two and carefully use forceps to pull the
BOTTOM membrane from the leaf. They should mount this on a clean slide, cover
with a drop of water and add a cover slip.
11. Have students view their slide under the microscope. Instruct them to draw a diagram
of what they see and label stomata and guard cells on their diagram.
12. Have students repeat the preparation of the slide using the TOP of the leaf. View the
slide under the microscope and draw a diagram of what they see.
13. Ask students to compare the two slides. (The slide of the top of the leaf has no
stomata and guard cells.)
14. Ask students to explain why they think the plant only has stomata and guard cells on
one side of the leaf. Have them share their answers with the class.
15. Ask students, “Why are the guard cells important for the plant? What do they
control?” Have students share their answers.
16. Ask students, “What types of things might move into or out of the guard cells? How
are these things important for photosynthesis?” Have students share their ideas with
the class. Reinforce the idea that oxygen is released by the plant as a product and
carbon dioxide is taken in by the plant as a reactant for photosynthesis.

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Relating Structure to Function in Cells – Grade 12
Part Four – Blood cells
17. Using the microscope and a prepared slide of a human blood smear, have students
identify different types of cells. They should see many red blood cells, such as
pink/red circles, but relatively few white blood cells in their sample.

Instructional Tip:
Blood carries many pathogens that students should not handle. Use professionally
prepared slides to avoid exposure.

18. Have students complete Attachment E, Blood Cells. Students should go to their
textbook as a resource and investigate the difference in function between red and
white blood cells.
19. Ask students to brainstorm, in pairs, why they think the cells are different in
appearance even though they are both types of blood cells. Give them five to ten
minutes to discuss. Ask them to share answers and keep a list on the board.
20. Upon completion of this part of the activity, have students use their text to verify or
refute the list of answers given by the class.
21. Make sure that you go over student results of this part of the activity. Stress to
students that they are researching why specialized cells are important and should be
finding out why red and white blood cells look the way they do (how structure is
related to function). Ask students to brainstorm why cardiac cells might have a large
number of mitochondria. Have them share answers with the entire class. Discuss
with students the fact that cardiac muscle needs a lot of energy to function properly,
so it has a large number of mitochondria.

Part Five – Synthesis of information
22. Give students a copy of Attachment G, Cell Specialization Graphic Organizer and
have them fill it out. You may choose to do this in the form of notes, or have students
do this independently. Make an overhead sheet of the blank graphic organizer, and
provide a copy for each student.
23. Discuss this graphic organizer with students. Ask if any students have any questions.
Explain anything that needs to be clarified
24. Students should begin to work on the post-assessment. Give each student a copy of
Attachment A, Post-Assessment.

Differentiated Instructional Support:
Instruction is differentiated according to learner needs, to help all learners either meet the
intent of the specified indicator(s) or, if the indicator is already met, to advance beyond
the specified indicator(s).
 Have students work in pairs while doing microscope work to enable those who are
proficient at using the microscope to help teach others how to focus and make
accurate drawings.

4
Relating Structure to Function in Cells – Grade 12
 If necessary, provide students with the “cell specialization” graphic organizer with the
notes already filled in. Have these students highlight sections as they are discussed,
to keep them on task.
 Provide students with a vocabulary list of the words in this lesson. Have them write
the definitions, making sure that they use the words correctly throughout the lesson.
 Provide students with the blank graphic organizer at the beginning of the activity, and
have them fill it in as the lesson is completed.
 Have students research some of the specialized structures of invertebrate animals to
use in their essays, providing examples of importance of the specialized structures for
defense, nutrition, response to the environment, etc. (Suggested examples: flame
cells in planaria; cnidocytes, ocelli, statocysts, water vascular system in sea stars)

Extension:
Have students look at different tissue samples, such as cuboidal epithelium,
pseudostratified columnar epithelium, adipose tissue, muscle, cartilage, etc. Have them
identify similarities and differences and relate structure to the function of each of these
types of tissue. This can be completed with samples from the Internet.

Homework Options and Home Connections:
Provide students with a handout on different types of tissue. Have them research (in their
text) the function, and find out if there is a key part of structure related to function in
these tissues.

Materials and Resources:
The inclusion of a specific resource in any lesson formulated by the Ohio Department of
Education should not be interpreted as an endorsement of that particular resource, or
any of its contents, by the Ohio Department of Education. The Ohio Department of
Education does not endorse any particular resource. The Web addresses listed are for a
given site’s main page, therefore, it may be necessary to search within that site to find the
specific information required for a given lesson. Please note that information published
on the Internet changes over time, therefore the links provided may no longer contain the
specific information related to a given lesson. Teachers are advised to preview all sites
before using them with students.

For the teacher: microscopes, slides, cover slips, lens paper, forceps, water,
pipette/dropper, prepared slides of blood smear, plant leaves (one-
two leaves per lab group), vascular plant stem cross section slides,
moss cross section slide

For the students: microscopes, slides, cover slips, lens paper, forceps, water,
pipette/dropper, prepared slides of blood smear, plant leaves(one-
two leaves per lab group), vascular plant stem cross section slides,
moss cross section slide

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Relating Structure to Function in Cells – Grade 12
Vocabulary:
 xylem
 phloem
 guard cell
 stomata
 osmosis
 vascular plant
 red blood cell
 white blood cell
 cell wall
 cell membrane
 chloroplast
 photosynthesis
 mitochondria

Technology Connections:
Have students investigate the Web for microscopic images of cells that illustrate the
specificity of the structures is related to the function of the cell.

Research Connections:
Marzano, R., Pickering, D., Pollock, J. (2001).Classroom Instruction that Works:
Research-Based Strategies for Increasing Student Achievement, Alexandria, Va:
Association for Supervision and Curriculum Development.

Identifying similarities and differences enhances students’ understanding of and ability to
use knowledge. This process includes comparing, classifying, creating metaphors and
creating analogies and may involve the following:
 Presenting students with explicit guidance in identifying similarities and differences;
 Asking students to independently identify similarities and differences;
 Representing similarities and differences in graphic or symbolic form.

General Tips:
 If possible, provide each student with a microscope, especially students who have not
had experience with microscopes. This way, all students will gain proficiency at the
use of the instrument and the amount of time spent waiting for someone else to finish
will be minimized.
 Check with local medical research labs, universities and community colleges for
prepared slides. They may have some prepared slides that they are willing to donate
to your school. Check with the American Red Cross about free literature that they
may have on blood and blood disorders/diseases.
 You can view stomata on leaves, that don’t have an easily removable membrane, by
putting two swipes of clear nail polish on the underside of the leaf and allowing it to

6
Relating Structure to Function in Cells – Grade 12
dry for 10-15 minutes. Peel it off and you have an imprint of the cells of the
underside, including the guard cells.
 When using the graphic organizer for note-taking, have students draw in a diagram of
each structure covered in the notes.

Attachments:
Attachment A, Post-Assessment
Attachment B, Post-Assessment Scoring Guidelines
Attachment C, T-Chart
Attachment D, Observing Stomata
Attachment E, Blood Cells
Attachment F, Blood Cells Key
Attachment G, Cell Specialization Graphic Organizer
Attachment H, Cell Specialization Graphic Organizer Key

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Relating Structure to Function in Cells – Grade 12
Attachment A
Post-Assessment

Relating Structure to Function

Directions: Provide five examples of cells or tissue and explain how the structure of the
cell relates to its function and aids the organism as a whole.

Your essay will be evaluated using the scoring guidelines below.

Level 4 Level 3 Level 2 Level 1
Depth of Scientific Scientific Scientific Scientific
Understanding information and information and information information
ideas about cell ideas about cell about cell about cell
specialization are specialization are specialization specialization
accurate and accurate. has occasional has major
thoughtfully Scientific inaccuracies or is inaccuracies or
explained. connections simplified. is overly
Scientific about cell Scientific simplified.
connections about specialization connections Scientific
cell specialization are identified. about cell connections
are correctly specialization about cell
identified and may be implied. specialization
discussed. are unclear or
absent.
Scientific Scientific Scientific Scientific
Communication information about information about information information
cell specialization is cell specialization about cell about cell
communicated is communicated specialization has specialization is
clearly and clearly. some clarity. unclear.
precisely, but may Presentation is Presentation has Presentation
also include effectively some focus and lacks focus and
inventive/expressive focused and organization. organization.
dimensions. organized.
Presentation is
effectively focused
and organized.
Adapted from Council of Chief State School Officers State Collaborative on Assessment
and Student Standards (SCASS) Science Project, April 1997.

8
Relating Structure to Function in Cells – Grade 12
Attachment B
Post-Assessment Scoring Guidelines

The scoring guidelines for the essay can be found in the students’ directions. Below are
the type of specialization features that could be highlighted in the essay. This is only a
partial list. Students could include other examples.

 Specialized cells provide a unique function in the organism in which they are found;
 Red blood cells are specialized because they carry oxygen to the body parts and
return carbon dioxide to the lungs;
 White blood cells are specialized because they recognize chemicals secreted by
microorganisms and are able to leave the blood to go to the area of the body where
microorganisms are located to initiate the immune response;
 Xylem is a specialized plant tissue that transports water through the plants;
 Phloem is a specialized plant tissue that transports food through the plant;
 Ocelli are specialized structures in cnidarians and planarians that help them recognize
light;
 Statocysts are specialized structures in cnidarians that help them recognize gravity.

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Relating Structure to Function in Cells – Grade 12
Attachment C
T-Chart

Mosses Vascular Plants

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Relating Structure to Function in Cells – Grade 12
Attachment D
Observing Stomata

Name ______________________

Observing Stomata

Plants contain many unique cellular structures that have specific functions. Two of these
structures are guard cells and stomata. A stoma (plural, stomata) is a pore in the leaf. It is
surrounded by two guard cells. In this activity, you will investigate the location, structure
and function of stomata and guard cells.
Materials: clean slides, cover slips, lens paper, plant leaf, forceps, microscope
Procedure:
1. Make sure that your slides are clean and free of fingerprints.
2. Gently break the leaf. Using the forceps, carefully peel the membrane on the
underside of the leaf and place it on your slide.
3. Cover the slide with a cover slip and view under high power. Make a detailed
drawing of what you see in the space below. Be sure to label your drawing correctly.
4. Repeat steps one to three, using a membrane from the top of the leaf.
5. Identify the guard cells and stoma on each sample and answer the questions below.

Data collection:
The purpose of stomata is to: _______________________________________________
______________________________________________________________________

Underside of leaf Top side of leaf
High Power High Power

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Relating Structure to Function in Cells – Grade 12
Attachment D (Continued)
Observing Stomata

Questions:
1. What is different about the top side and the underside of the leaf?

2. Why do you think the two sides are different?

3. Identify the stoma and the guard cells.

4. Using your textbook, identify the function of the stoma and the guard cells.

5. Think about the structure/shape of the guard cells and the stoma. How does this
relate to the function of these structures?

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Relating Structure to Function in Cells – Grade 12
Attachment E
Blood Cells
Name ____________________

Anatomy and Physiology
Blood cells

Directions: Look at the slides of blood. Focus them on low power, then switch to high
power before you draw them. Draw each, and answer the questions that follow.

Questions:
1. On the drawing of the blood, label some red blood cells and some white blood cells.

2. What is the function of the red blood cell?

3. What is the function of the white blood cell?

4. What are the types of white blood cells that you can see in your slide?

5. What happens within your body if you have too many red blood cells? Explain.

6. What is happening within your body if you have too many white blood cells?
Explain.

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Relating Structure to Function in Cells – Grade 12
Attachment F
Blood Cells Key

1. Bloodsmear drawing with cells labeled.

2. Red blood cells deliver oxygen and remove waste.

3. White blood cells are part of the immune system and they help to fight disease.

4. Lymphocytes and neutrophils will be the most common cells.

5. Too many red blood cells can result in a condition called polycythaemia. Excess red
blood cells cause the blood to thicken and blood clots become problematic.

6. Too many white blood cells indicates that the body is fighting an infection or
disease. If the white blood cell count remains consistently high, it may be an
indication of leukemia.

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Relating Structure to Function in Cells – Grade 12
Attachment G
Cell Specialization Graphic Organizer

Cell Specialization

DRAFT 15
Relating Structure to Function in Cells – Grade 12
Attachment H
Cell Specialization Graphic
Cell Specialization
Organizer Key

Stoma and Guard Cells Vascular Tissue, Plant Blood Cells Nematocysts

Stoma – pore in plant cells on Tissue specialized for Red blood cells – contain Specialized cells in jelly
underside of leaf to allow carrying water and nutrients no nucleus; made in red fish that contain poison
passage of gases such as CO2 in plants. bone marrow; specialized to stingers that jet outward
carry oxygen throughout the when the jellyfish is
Guard Cell – one of two cells Xylem – for transport of body; found in very large threatened.
that surround stoma and water from roots to leaves; numbers in blood samples.
control the size of the stoma. formed from tracheids to be Nematocyst stingers turn
Stoma is larger during the one long, straw-like tube in White blood cells – contain inward, unless the jellyfish
day, when plant takes in large plant. a nucleus and DNA, is threatened, then they
amounts of CO2 for Phloem – transport nutrients specialized to fight disease; shoot outward with their
photosynthesis. and carbohydrates made by numbers of white blood poison.
photosynthesis from leaves to cells varies with the health
stem and roots of plant. of the individual.

Diagram of stoma and guard Diagram of vascular tissue Diagram of red and white Diagram of nematocysts
cells blood cells

DRAFT 16