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Name: _______________________
Human Epithelial Cells & Plant Cells
Background: Although plant and animal cells have many structures in common, they also have
basic differences. Plant cells have a rigid cell wall and chlorophyll containing structures called
chloroplasts. Animal cells lack a cell wall and chloroplasts. They also lack the central vacuole
common to plant cells.
You will observe and compare producer (plant) and consumer (animal) cells. You will first
examine epithelial cells from the inside of your cheek. Epithelium is a type of tissue that covers
the surfaces of many organs and cavities of the body.
You will then examine cells from a leaf. Plant cells are green because they contain the pigment
chlorophyll. Chlorophyll, which is found in chloroplasts within each cell, enables plants to
manufacture their own food through the process of photosynthesis.
Objectives: In this activity you will:
1. Observe human epithelial cells.
2. Observe plant cells.
3. Describe the differences between plant and animal cells.
Materials:
Microscope
Slides
Cover slip
Toothpicks
Water
Pipette
Plant leaves
Forceps/tweezers
Iodine solution
Part I: Human Epithelial Cells
Procedure: To observe human epithelial cells under a microscope, you must make a temporary
(wet mount) slide of cheek cells from the inside lining of your mouth.
 To obtain epithelial cells, gently scrape the inside of your cheek with a clean toothpick
being careful not to stab yourself or cause bleeding. Stir the material from the toothpick
in a drop of water on a clean slide.
 Add a drop of iodine to the slide. Stir again and then throw the toothpick into the trash
can.
 Place a cover slip on the slide.
 Examine the slide under low power magnification.
 When you find some cells that are separate from each other, examine them under high
power magnification. (Remember to focus on Medium power before turning to high
power).
 In the space provided, make a drawing of two to three human epithelial cells separate
from each other.
Label the following cell structures in your drawing: cell membrane, cytoplasm, nucleus, &
nuclear membrane.
Individual Human Epithelial Cells:
High Power
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Human Epithelial Cells: Grouped
High power
Find several human epithelial cells “grouped” together to form the epithelial tissue lining
of your mouth.
In the space provided, make a drawing of a group of human epithelial cells in the tissue
arrangement. Be sure to label all visible structures.
Part II: Plant Cells
Procedure: To observe the plant cells under a microscope, you must make a temporary (wet
mount) slide of a leaf.
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Break off a small piece of leaf.
With tweezers, place the leaf in a drop of water on a clean slide.
Lower the cover slip over the specimen. Examine the plant cells on low power. Adjust
the diaphragm to provide the best light.
After examining the leaf on low power, examine with the high power magnification.
Plant leaves are typical producer cells surrounded by a thick non-living boundary called
the cell wall. Pressed tightly against the cell wall, is a very thin, living cell membrane.
The central part of the cell consists of a large fluid filled structure called the central
vacuole. Located within the clear, fluid cytoplasm are numerous small, green bodies
containing the pigment chlorophyll. These small, green bodies are chloroplasts and are
the structures in which photosynthesis occurs. The numerous chloroplasts often make it
difficult to observe other cell structures in the plant leaf cells. In order to see the
nucleus, nucleoli, and central vacuole more clearly, you must use a stain.
As you examine the leaf cells, you may see the green chloroplasts moving around in the
cytoplasm. This movement is due to the “flowing” of the cytoplasm and is called
cytoplasm streaming or cyclosis. If you do not see cytoplasmic movement, allow the
leaf to warm under the heat of a bright lamp for a few minutes. Do not allow the slide to
dry out. After warming, examine the leaf again under high power.
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Now, place a drop of iodine to stain the leaf. Wait a minute or so for the iodine to
penetrate into the cells.
Examine the slide under low power magnification. Then examine the leaf under high
power magnification. (Remember to focus on Medium power before turning to high
power).
In the space provided below, make a drawing of a single plant cell that has been stained
with iodine while viewed under high power.
In the space provided, make a drawing of a single plant cell and label the following:
chloroplasts, cell wall, cell membrane (although not visible), and cytoplasm.
Next, make a drawing of several plant cells showing their arrangement in the leaf.
Leaf Single Cell: High Power
Several Leaf Cells: High Power
Analysis:
1. Describe the general appearance of animal epithelial cells: ___________________________
______________________________________________________________________________
2. Describe the general appearance of plant leaf cells: __________________________________
______________________________________________________________________________
3. Which of the cells that you viewed are found in producers? ___________________________
4. Which of the cells that you viewed are found in a consumer? __________________________
5. What cell structure is present in leaf cell that is not present in human epithelial cells?
____________________
6. Do plant cells have a cell membrane? __________ If yes, explain why you are unable to
observe it with a microscope? _____________________________________________________
______________________________________________________________________________
7. Are the cells you viewed in this lab classified as prokaryotic or eukaryotic? ______________
8. What evidence did you observe to support your answer to questions #7? ________________
______________________________________________________________________________
9. What is the name of the outer boundary of a human epithelial cell? _____________________
10. What is the name of the outer boundary of a plant cell? _____________________________
11. As you observed the plant cell you probably noticed movement of the green organelles
within the cytoplasm. Explain how movement of the organelles is possible. ________________
_____________________________________________________________________________
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12. What is the name given to the small, green oval shaped organelles found in the cytoplasm of
the plant cells? _________________________________________
What is the function of this green organelle? _________________________________________
______________________________________________________________________________
13. Create a Venn-Diagram comparing and contrasting an animal cell and a plant cell.
Animal Cells
Plant Cells