Name: __________________________________
Observing Cells Pre-Lab
Part 1: LABELING MICROSCOPES
A
Letter
Part
Function
A
B
B
C
C
D
E
F
H
G
D
E
F
G
H
I. CALCULATING MAGNIFICATION
Eyepiece magnification
______________
(X)
Objective magnification
______________
=
Total Magnification
_____________X
Eyepiece magnification
______________
(X)
Objective magnification
______________
=
Total Magnification
_____________X
Eyepiece magnification
______________
(X)
Objective magnification
______________
=
Total Magnification
_____________X
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Part 2: LABORATORY DRAWINGS
 Laboratory drawings can be done in several ways depending on the lab.
 Some drawings are made in circles that represent the microscope field of view.
 Always label the magnification you used when doing any laboratory drawing.
 Most laboratory drawings are labeled. Use the following guidelines to help make
your laboratory drawings clear and legible:
o Make all drawings in pencil.
o Label lines should point to the center of the structure being labeled.
o Do not write on the label lines.
o Print all labels horizontally.
o Label the right-hand side of the drawing, if possible.
o Do not cross label lines.
The following laboratory drawing was completed without using the guidelines for
laboratory drawings.
Circle 5 things that are wrong with this drawing.
Onion cell magnification:_____X
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Name: ________________________________________ Period: ___________
Observing Cells Lab
Introduction:
Living things are made of cells. All cells have parts that do certain jobs. These parts are called
organelles. Cells have an outer covering called a cell membrane. Cell membranes give the cells their
shape and control what enters and leaves the cell. The clear, jelly-like material inside the cell is the
cytoplasm. Also present in all eukaryotic cells is the nucleus. The job of the nucleus is to control the
activities of the cell. Plant cells have two organelles that animal cells do not have, cell wall and
chloroplasts. The cell wall is what gives plant cells their shape. Chloroplasts are the site of
photosynthesis in the plant. The chloroplast contains the pigment chlorophyll. This is the pigment
that gives the cell its color and allows it to use the sun to make energy. Plant cells also have an
organelle called a vacuole, which is a large sac that stores water.
Purpose:
The purpose of this laboratory exercise is to observe and identify structures of cells. You will
also learn about the structural difference between plant and animal cells.
Materials:
slide
dropper & water
frog blood slides
cover slip
microscope
onion slides
tooth picks
methylene blue (stain)
Elodea
paper towels
Part 1: Onion Cells
Procedure:
1. Prepare a wet mount of the onion.
2. Examine the slide under scanning power.
3. Examine the slide under low power and high power. In the space below, draw the onion cells as
your see them under high power. Use good scientific drawing procedures. Make sure you record
the total magnification of each diagram.
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Part 2: Elodea cells
Procedure:
4. Prepare a wet mount of an Elodea leaf.
5. Examine the slide under scanning power.
6. Examine the slide under low power and high power. In the space below, draw the Elodea cells as
your see them under high power. Label the cell wall, a chloroplast, and cytoplasm. Use good
scientific drawing procedures. Make sure you record the total magnification of each diagram.
7. Look closely at the cells. Do you observe any movement within the cells? If so, describe the
movement. _________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
Analysis Questions:
1. When you looked at the Elodea cells you should have seen movement. This movement is called
cytoplasmic streaming. Describe the movement you saw below:_________________________
_____________________________________________________________________________
_____________________________________________________________________________
2. What is the small green organelle visible in the Elodea cells? ___________________________
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Part 3: Cheek Cells
1. Prepare a slide of cheek epithelial cells. Directions are as follows:
a. Obtain a toothpick and gently scrape the inside of your cheek with the toothpick.
b. Place the scraping on a clean, dry slide.
c. Discard the toothpick into the garbage can.
d. Add a drop of methylene blue and cover with a cover slip.
2. Observe under scanning power, low power, and then high power.
3. Draw the cheek cells as you see them on high power.
4. Label the nucleus, cytoplasm, and cell membrane.
5. Discard the slide of cheek cells into the broken glass container (green bucket).
Part 4: Bacterial Cells
1. Obtain a slide of different bacterial types. There are three types of bacteria to observe on each
slide.
2. Observe the bacterial cells under scanning power, low power, and high power.
3. Draw the three different types bacterial cells as you see them on high power. Label the cell
membrane.
4. What are the three shapes are the bacterial cells?
__________________________________________________________________________
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Analysis Questions:
1. Which of the slides you looked at were plant cells and which were animal cells?_____
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
2. What were some of the differences between plant and animal cells that you observed while
using the microscope?_______________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
3. If you got a “mystery” slide and you had to determine if it contained plant cells or animal cells,
what would you look for to determine what type of cells it contained?_________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
4. Which of the slides that you looked at were prokaryotic cells? How did you know? Explain.
_________________________________________________________________________
_________________________________________________________________________
5. Which of the slides that you looked at were eukaryotic cells? How did you know? Explain.
_________________________________________________________________________
_________________________________________________________________________
6. How were the bacterial cells different from the plant and animal cells you looked at?
____________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
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Conclusion Questions:
1. How did the invention of the light microscope change the way scientists looked at the world?
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
2. What are the major differences between plant and animal cells?______________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
3. What are the major difference between prokaryotic and eukaryotic cells?_______________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
IF TIME PERMITS, obtain a survey kit and start exploring!!
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