Comparing Animal and Plant Cells
Background:
Cells are the basic units of structure and function of all living things. There are
two major divisions into which all cells fall – Prokaryotic and Eukaryotic. Prokaryotic
cells are cells that lack a nucleus and membrane bound organelles. Bacteria and related
microorganisms are prokaryotes. Eukaryotic cells are cells that contain a nucleus and
membrane bound organelles. Organisms such as animals, plants, fungi, and protists are
all eukaryotes. In this investigation, you will observe slides of animal and plant cells to
determine differences among them.
Purpose:
Examine the similarities and differences between the structure of cells in animals
and the structure of cells in plants.
Hypothesis:
Make a statement to describe what you believe is the difference between plant and
animal cells
Materials:
Microscopes, microscope slides, cover slips, pipettes, elodea leaf, cheek cells
Procedure:
Part A Animal Cells:
You are required to make a wet mount of a cheek cell. To do this you must use a
toothpick and rub it on the inside of your cheek. Take the toothpick and smear the cells
onto a microscope slide, place 1 drop of water, and 1 drop of blue stain on the cells. Put
the cover slip onto the slide. Now examine this slide of cells under low power. Locate
cells that are separate from each other and place them in the center of the field of view.
Examine the cells under high power. In your lab report, make a drawing of two or
three cells as they appear. Identify and label the cell membrane, the cytoplasm, and
the nucleus of one of the cells.
Part B Plant Cells
Tear off a small leaf of the elodea plant. Place the leaf in a drop of water on a
slide. Place a cover slip on top of the leaf, and observe the leaf under low power. Locate
a cell that you can see clearly and move the slide in the center of the field of view.
Examine the cells under high power. In your lab report, make a drawing of two or
three cells as they appear. Identify and label the cell wall, cell membrane, the
chloroplast, and the nucleus of one of the cells.
The chloroplasts may be moving in some of the cells. If you observe no
movement, warm the slide in your hand or shine a lamp on it for a minute or two. Look
for the movement of the cell’s contents. This movement is called cytoplasmic streaming.
Because the cell membrane is pressed against the cell wall you may not see it. Also, the
chloroplasts may hide other organelles. You can make the cell membrane, vacuole,
nucleus, and nucleolus more visible by making a stained wet mount using Iodine. Once
again examine the cells under high power. In your lab report, make a drawing of
two or three cells as they appear. Identify and label the cell wall, cell membrane,
the chloroplast, and the nucleus of one of the cells.
Data:
Make a picture of the cells from the three steps in the procedures
Animal Cell
Plant Cell
Plant Cell w/ Iodine
Analysis:
1. According to your observations in this investigation, list several ways that plant
and animal cells are structurally similar and several ways that they are different.
2. What do you think might be the function of cytoplasmic streaming in a plant cell?
3. Which organelles did you not see in the cells? Why do you think you were unable
to see these organelles in your slides?
4. Why are cell walls and chloroplast not found in animal cells?
Conclusion:
Write your conclusion to this lab in your own words. Summarize what the lab
was about. Include anything that you have learned from the lab. Tell me if your
hypothesis was correct or incorrect. You can restate your results in paragraph format.
You can include anything that you think you did wrong that might affect your results.
You can state if there are any changes you would make to this lab to make it better. (Do
not just say this was a fun lab and I learned about cells. If you say you learned
about cells, tell me something that you learned about them.)