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Name _______________________________________________
Observing Animal Cells.2014
Date ____________
Activity: Observing Animal Cells
Goal: To observe, identify, and describe the main parts of a
typical animal cell (Example: cheek cells/human epithelial
cells).
Background Information: The most obvious structures of an animal cell are the cell membrane,
cytoplasm, and the nucleus. These structures are easy to see under a school microscope.
Students can collect epithelial cells from their mouths by gently scraping their inner cheeks.
Epithelial cells are used for protection and forming the lining of many body surfaces. They can be
removed easily and are replaced quickly.
Materials: A blank slide, flat-edged tooth pick, cover slip, iodine solution or methylene blue stain
Note: Please advise your teacher if you are allergic to iodine and/or shellfish!!!
Procedure:
1. What I Know: Write two sentences explaining what you already know about animal cells.
2. Add a small drop of iodine or methylene blue to a clean, blank slide. The purpose of the
iodine is to stain the cells so that there is contrast among the different cell parts. For
example, the nucleus will absorb more of the iodine and appear a brownish color in
contrast to the cytoplasm of the cell.
3. Gently scrape the inside of you cheek two or three times with the broad end of a flat-edged
toothpick.
4. Spread the wet material that you scraped from your cheek across the blank slide. Do not
apply too much pressure to the toothpick or slide. (Since these cells are being removed
from their natural position in your mouth, their shape may become distorted if you push
them around too much.
5. Beginning with 40X, observe the cheek cells and draw what you see.
6. What I Observed: Draw your observations only at 40X and 100X. Label the cell
membrane, cytoplasm, and nucleus of one cheek cell in one of your drawings. Write a
caption describing your drawings.
______ X
Cheek Cells
______ X
Cheek Cells
Caption: Write a caption that describes your observation.
7. Questions: Answer the following in complete sentences.
a. Describe the shape of the cells you observed. (Example: The shape of the cells I
observed are ______________.)
b. Describe the function of each of the cell parts you observed.
c. Describe something that surprised you about your observations of the animal
cells.
d. Why is the methylene blue necessary?
8. What I Wonder: Pose at least one question that arises from this activity or topic. It should
be a “how” or “why” question
9. What I Learned:
Claim: What did you learn?
1.
Evidence: How do you know that?
Use your observations. Be specific.
1.
2.
2.
1.
2.
Claim and Evidence Writing Prompts: Use the following prompts to help you construct
your lab conclusion, What I Learned.

Goal: State the goal of this lesson.
The goal of this lesson is…

Claim: What did you learn from the activity that satisfies the goal of this lesson? This
is an I Learned statement.
I learned that…

Evidence: How can you prove from your observations (data) you collected that you
learned what you claim? This can be a general statement that you will explain in
detail in your explanation.
I know this because….

Explanation/Reasoning: Use specific data from your observations to support your
claim and describe the evidence. Use details to support your claim. Add information
from that you learned from our class discussions, text book or other resources that
will help support your claim or enhance your explanation.
Name ____________________________________
Lab Activity: Observing Animal Cells
Date __________________
What I Learned: Write a summary of what you learned by completing this activity. The
summary should include a claim that is related to the goal of the lesson, provides evidence from
your observations, and offers an explanation that links your claim to the evidence.