Download Comparing Plant and Animal Cells Lab

Name _______________________________ Date _____________
Bio Section ______
Score ________
Comparing Bacteria, Animal, and Plant Cells
Objective: How are bacteria, plant and animal cells alike? How are they different? How can you use a microscope to answer
these questions?
Procedure: In this lab, you will view bacteria, human, and plant cells on prepared slides. Careful observation should reveal
similarities and differences between the cells. You will also label components of the cell, using a ruler to connect the term
with the structure in your drawing. If the cell you observe does NOT have any of the characteristics that you’re asked to
label, don’t label it. Look at the name on the slide and write it down to ID which type of cell you examined (ex. cheek cell).
Finally, you will need to include the magnification at each level of your observations (ex. 100x).
Microscope Information: The light microscope has two sets of lenses: the eyepiece (10x) and the objectives. The total
magnification of the specimen is calculated by multiplying the magnification of each set of lenses-
Total Magnification = magnification of the eyepiece X magnification of the objective
There are four objective lenses, however, you will only be using the first three. Do not use the 100x oil immersion lens at
this time.
Indicate here which type of eyepiece you have: monocular or binocular (circle).
Depth of focus:
Adapted from Biology Corner
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Name _______________________________ Date _____________
Bio Section ______
Score ________
Bacteria Cells
Type________________________________________
Obtain a slide composed of bacteria cells. These cells are stained red/pink. Perfect circles with black outlines are air bubbles.
Don't sketch those. Sketch the bacteria cells under high power. Make sure you are drawing your cells to SCALE - that is, the
size of your drawing should reflect the size that you view them in the microscope, or in its field of view (the area of the
image that you see).
40x
1. Identify the CELL MEMBRANE on your
drawing.
2. Identify the CYTOPLASM (area) on your
drawing.
Total Magnification ______________
Animal Cells
Type________________________________________
Sketch the cells under low and high power. Make sure you are drawing your cells to SCALE - that is, the size of your
drawing should reflect the size that you view them in the microscope, or in its field of view (the area of the image that you
see). Cells should look bigger under higher power as the field of view decreases.
10x
40x
1. Identify the NUCLEUS on your drawing.
2. Identify the CELL MEMBRANE on your
drawing.
3. Identify the CYTOPLASM (area) on your
drawing.
Total Magnification ______________
Total Magnification ______________
Plant Cells
Type________________________________________
Obtain a slide composed of plant cells. Sketch your cells under low and high power, also paying attention to scale.
10x
40x
1. Identify the CHLOROPLASTS on your
drawing.
2. Identify the CELL WALL on your drawing.
3. Identify the CYTOPLASM (area) on your
drawing.
Total Magnification ______________
Total Magnification ______________
4. Identify the CENTRAL VACUOLE on your
drawing.
WET MOUNTS (FRESH SLIDES)
It is possible to take a look at fresh samples under the microscope as
well. You can take a small sample, add water to it, cover it with a
microscope slip, and take a look at it under the microscope. It’s pretty easy! Here are the steps in general.
Adapted from Biology Corner
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Name _______________________________ Date _____________
Bio Section ______
Score ________
1. Use a clean microscope slide
2. Place the specimen on the center of the
slide. It should be thin enough that cover
slip is flat
3. Add 1 drop of stain and 1-3 drops of water. If
you add too much water, you might lose the
specimen
4. Place the cover slip over the specimen—
--- Place one edge down and hold the top at
a 45 degree angle. Then let the top of the
slip drop (See figure below)
http://sjesci.wikispaces.com/file/view/wetmount.jpg/156592229/wetmount.jpg
http://www.ecologycenter.org/tfs/images/2005fall/wet_mount.jpg
Cheek Cells
Gently scrape a clean toothpick over the inside of your cheek and swirl it in a drop of methylene blue to stain the cells
(otherwise they will be clear and difficult to see). You are looking for light colored blobs with dark spots in them. Perfect
circles with black outlines are air bubbles. Don't sketch those. Sketch the cheek cells under low and high power. Make sure
you are drawing your cells to SCALE - that is, the size of your drawing should reflect the size that you view them in the
microscope.
Low Power
High Power
1. Identify the NUCLEUS on your drawing.
2. Identify the CELL MEMBRANE on your
drawing.
3. Identify the CYTOPLASM (area) on your
drawing.
Total Magnification ______________
Total Magnification ______________
Review Questions
1. If the eyepiece on a microscope has a magnification of 10x, what is the total magnification with a 36x objective?
2. With the same eyepiece, what is the power of the objective lens if the total magnification is 1000x?
Adapted from Biology Corner
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Name _______________________________ Date _____________
Bio Section ______
Score ________
3. Why is it important to center a specimen on low power before attempting to focus on it at high power? Use field
of view in your answer.
4. A student focuses on a specimen at low power and carefully centers it before changing to high power, however, he
doesn’t see the part of the specimen that he was interested in. What might be the problem? There are two
possibilities.
Adapted from Biology Corner
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Name _______________________________ Date _____________
Bio Section ______
Score ________
Analysis Questions
1. The mouth is the first site of chemical digestion in humans. Keeping this in mind, what organelle do you think
would be numerous inside the cells of your mouth? Why?
2. Which organelles would you expect to be most numerous in muscle cells? Why?
3. List the organelles that were NOT visible but should have been in the animal cell.
4. Why do you think these organelles are not visible?
5. Pick either the animal or plant cell. Is it a eukaryote or prokaryote? How can you tell? Explain using information
from your own observations.
Adapted from Biology Corner
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Name _______________________________ Date _____________
Bio Section ______
Score ________
2. Create a Venn Diagram to compare/contrast the bacteria, animal, and plant cells. Start with the structures you observed
in lab today, then move onto what you’ve read about in your textbook. Remember, things that they have in common go into
the overlapping area, things that are different go in the non-overlapping area.
Animals
Plants
Bacteria
Adapted from Biology Corner
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