Name ___________________________________
Mrs. Geithner-Marron (Bio 300)
Cells: The Basic Unit of Life Microscope Lab
Date _________
Period ________
Materials
 microscope
 slides
 razor blade (single-edge) or
scalpel
 coverslips
 iodine stain in dropper bottle
 water
 methylene blue stain in
 cork
dropper bottle
 onion
 prepared slide of frog blood
 Elodea
 toothpick
Introduction
When different types of cells are viewed under a microscope,
different cell parts can be seen. Certain living cells are best for showing
parts like a nucleus or cell membrane. Once-living (preserved) cells are
best for showing parts such as a cell wall. Cells from producer organisms
(plants) will show parts such as chloroplasts and cell walls. Most consumer
organisms (such as animals) have cells that do not have these parts,
although fungi have cell walls. We will not view fungi in this lab.
In this investigation, you will:
 observe a variety of living and once living materials under the
microscope.
 study and locate under the microscope six specific cell parts (cell
wall, cell membrane, cytoplasm, nucleus, nucleolus, and chloroplasts).
 compare the cell parts found in plant and animal cells.
Name ___________________________________
Mrs. Geithner-Marron (Bio 300)
Cells: The Basic Unit of Life Microscope Lab
Date _________
Period ________
Part 1: The Cell Wall
Cork cells are excellent for studying a cell part common to all plant cells. This part is the
cell wall. In a cork cell, the cell wall is easily visible. The cork is no longer living. The cell wall
remains as the only evidence of once living materials.
1. Obtain a very thin slice of cork and prepare a wet mount as
shown to the right.
2. Locate and examine the cork under low power.
3. Switch carefully (while looking from the side at stage level) to
high power and refocus using the fine-adjustment knob.
4. Draw several cork cells as they appear under high power.
a. Be sure to draw your cells neatly, accurately, and as detailed as possible. Your
drawing should look like what you see, not just some random line, dots, etc.
5. Label the cell wall.
Analysis, Part 1: Answer the following questions.
1. Is the cork you viewed alive? ______________________________________________
2. What are the small “boxes” that you (like Robert Hooke) saw in the cork called? ________
3. Are these “boxes” you looked at filled with living material or are they empty? __________
4. What part is all that remains of the cell? _____________________________________
5. Is cork part of a plant or animal? ___________________________________________
6. Do animal cells have cell walls? _____________________________________________
7. The cell wall is made up of a carbohydrate called ________________________________
Name ___________________________________
Mrs. Geithner-Marron (Bio 300)
Cells: The Basic Unit of Life Microscope Lab
Date _________
Period ________
Part 2: The Cell Membrane and Cytoplasm
Human cheek cells may be used for viewing the cell
membrane and cytoplasm. A cell membrane is a thin outer
boundary which surrounds the cell and separates it from
neighboring cells. Cytoplasm is the jelly-like inner portion
of the cell.
1. Use the pictures to the right as a guide when
preparing your slide.
2. Place a drop of methylene blue stain in the center of
a slide. (Picture A)
3. Gently rub the inside of your cheek with the end of a
toothpick. (Picture B)
a. You will not be able to see anything on the
toothpick when you remove it from your mouth.
4. Dip the toothpick into the stain on the slide and gently mix once or twice. (Picture C).
5. Add a coverslip over the stain.
6. Locate and examine the cheek cells under low power. Try to locate and examine cells that
are separated from each other rather than those that are clumped together.
7. Switch carefully (while looking from the side at stage level) to high power and refocus using
the fine-adjustment knob.
8. Draw several cheek cells as they appear under high power.
a. Be sure to draw your cells neatly, accurately, and as detailed as possible. Your
drawing should look like what you see, not just some random line, dots, etc.
9. Label the cell membrane and cytoplasm.
Name ___________________________________
Mrs. Geithner-Marron (Bio 300)
Cells: The Basic Unit of Life Microscope Lab
Date _________
Period ________
Analysis, Part 2: Answer the following questions.
1. Describe the shape of a cheek cell. __________________________________________
2. Are cheek cells found in plants or animals? ____________________________________
3. Do cheek cells have cell walls? ______________________________________________
a. Why/why not? ____________________________________________________
4. Are cheek cells alive (while they are in your mouth)? _____________________________
5. Where is the cell membrane located? ________________________________________
6. What is the function (job) of the cell membrane? _______________________________
7. Where is the cytoplasm located? ___________________________________________
8. What does cytoplasm look like? (Remember: The color is due to the methylene blue stain.)
____________________________________________________________________
9. What is the job of the cytoplasm? __________________________________________
10. Why did we add stain to the cheek cells? _____________________________________
Name ___________________________________
Mrs. Geithner-Marron (Bio 300)
Cells: The Basic Unit of Life Microscope Lab
Date _________
Period ________
Part 3: The Nucleus, Nucleolus, and Nuclear Membrane
Onion cells may be used to show a cell’s nucleus and nucleolus. These two structures appear
within most living cells. There may be several nucleoli (plural of nucleolus) appearing as tiny dots
within each cell’s nucleus. The nucleus will appear as a round structure inside each cell.
Use the pictures to the right as a guide when preparing your
slide.
1. Obtain a piece of onion and snap it in half as shown to
the right. (Picture A)
2. Use your fingernail to peel off a thin layer of onion
tissue (from the side that is curved inward). (This layer
will look almost like tissue paper.) (Picture B)
3. Place one think onion layer onto the slide. Make sure to
uncurl or unfold any overlapped portion of the onion
so that the tissue lays flat.
4. Place a drop or two of iodine stain on the onion tissue.
a. CAUTION: If iodine spillage occurs, notify the teacher immediately. Iodine can stain
your skin (rinse thoroughly if it gets on your skin. Iodine can also stain clothes.
5. Add a coverslip over the stain.
a. Tap the coverslip gently with the eraser end of your pencil to drive out any air
bubbles if needed.
6. Locate and examine the onion cells under low power. Note the brick wall appearance of
the cells with cell walls separating the cells.
7. Switch carefully (while looking from the side at stage level) to high power and refocus using
the fine-adjustment knob.
8. Locate a small round structure, the nucleus, within each cell. You will probably need to
focus up and down to get the best view of the nucleus.
9. Also, observe the tiny dots within the nucleus. These are the nucleoli (plural of nucleolus).
10. Also observe the outer edge of the nucleus. This thin covering is called the nuclear
membrane.
11. Draw a SINGLE onion cell as it appears under high power.
a. Be sure to draw your cells neatly, accurately, and as detailed as possible. Your
drawing should look like what you see, not just some random line, dots, etc.
12. Label the cell wall, nucleus, nucleolus, and nuclear membrane.
Name ___________________________________
Mrs. Geithner-Marron (Bio 300)
Cells: The Basic Unit of Life Microscope Lab
Date _________
Period ________
Analysis, Part 3: Answer the following questions.
1. Describe the shape of an onion cell. __________________________________________
2. Are onion cells found in plants or animals? _____________________________________
3. Do onion cells have cell walls? ______________________________________________
a. Why/why not? ____________________________________________________
4. Describe the shape of the nucleus in the onion cell. ______________________________
5. The nucleus is found “floating” in the ________________________________ of the cell.
6. What is the function (job) of the nucleus? ____________________________________
7. Describe the shape of the nucleolus in the onion cell. _____________________________
8. The nucleolus is found within the ___________________________________ of the cell.
9. What is the function (job) of the nucleolus? ___________________________________
10. What structure separates the inside of the nucleus from the cytoplasm within the cell?
____________________________________________________________________
11. Why did we add stain to the onion cells? _____________________________________
Name ___________________________________
Mrs. Geithner-Marron (Bio 300)
Cells: The Basic Unit of Life Microscope Lab
Date _________
Period ________
Part 4: Chloroplasts
Another cell part found in the cells of many producers is the green chloroplasts. Elodea, a
common water plant, shows these important structures clearly.
1. Obtain a leaflet of an Elodea plant, and prepare a
wet mount as shown to the right.
2. Locate and examine the Elodea under low power.
3. Switch carefully (while looking from the side at
stage level) to high power and refocus using the
fine-adjustment knob.
4. Note the small green organelles inside each cell.
These are the chloroplasts. Movement of the
chloroplasts within the cell (cyclosis) often can be
observed. Attempt to locate moving chloroplasts.
5. Draw a SINGLE Elodea cell as it appears under
high power.
a. Be sure to draw your cells neatly, accurately, and as detailed as possible. Your
drawing should look like what you see, not just some random line, dots, etc.
6. Label the cell wall and chloroplasts.
Name ___________________________________
Mrs. Geithner-Marron (Bio 300)
Cells: The Basic Unit of Life Microscope Lab
Date _________
Period ________
Analysis, Part 4: Answer the following questions.
1. Describe the shape of an Elodea cell. ________________________________________
2. Is Elodea a plant or animal? _______________________________________________
3. Do Elodea cells have cell walls? _____________________________________________
a. Why/why not? ____________________________________________________
4. What color are the chloroplasts? ___________________________________________
5. What shape are the chloroplasts? ___________________________________________
6. The chloroplasts are found “floating” in the ___________________________ of the cell.
7. What is the function (job) of the chloroplasts? _________________________________
8. Are chloroplasts usually found in the cells of consumers (animals)? ___________________
a. Why/why not? ____________________________________________________
Name ___________________________________
Mrs. Geithner-Marron (Bio 300)
Cells: The Basic Unit of Life Microscope Lab
Date _________
Period ________
Part 5: Plant or Animal Cell?
1. Obtain a prepared slide of frog blood.
2. Locate and examine the frog blood cells under low power. Note that the colors you see are
not natural. Stains have been added to these cells to make viewing easier.
3. Switch carefully (while looking from the side at stage level) to high power and refocus using
the fine-adjustment knob.
4. Draw several frog blood cells as they appear under high power.
a. Be sure to draw your cells neatly, accurately, and as detailed as possible. Your
drawing should look like what you see, not just some random line, dots, etc.
5. Label the cell wall, cell membrane, cytoplasm, chloroplasts, and nucleus ONLY if these
parts are present! Not all of these parts may be seen in frog blood.
Analysis, Part 5: Answer the following questions.
1. Describe the shape of frog blood cells. _______________________________________
2. Do frog blood cells have cell walls? __________________________________________
a. Why/why not? ____________________________________________________
3. Do frog blood cells have chloroplasts? ________________________________________
a. Explain your reasoning. ______________________________________________
4. What structure separates the inside of the frog blood cell from its environment?
____________________________________________________________________
5. What is the name of the dark, oval-shaped part found in the center of the frog blood cell?
____________________________________________________________________
Name ___________________________________
Mrs. Geithner-Marron (Bio 300)
Cells: The Basic Unit of Life Microscope Lab
Date _________
Period ________
Analysis, General: Answer the following questions.
1. Complete this chart. Place a check mark in the boxes to indicate if a structure is found in a
plant cell or animal cell.
2. How are cork, onion, and Elodea cells alike? ____________________________________
____________________________________________________________________
a. What cell parts do they have in common? _________________________________
________________________________________________________________
3. How are cheek and frog blood cells alike? _____________________________________
____________________________________________________________________
a. What cell parts do they have in common? _________________________________
________________________________________________________________
4. How are cork, onion, and Elodea cells different from cheek and frog blood cells?
____________________________________________________________________
____________________________________________________________________
a. What cell parts do all these cells have in common? __________________________
________________________________________________________________
b. What cell parts are found in cork, onion, and Elodea cells but not in cheek or frog
blood cells? ______________________________________________________
________________________________________________________________
c. What cell parts are found in cheek and frog blood cells but not in cork, onion, or
Elodea cells?______________________________________________________
________________________________________________________________
Name ___________________________________
Mrs. Geithner-Marron (Bio 300)
Cells: The Basic Unit of Life Microscope Lab
Date _________
Period ________
5. Label the diagram of a typical “plant” cell with the following parts:
ribosomes, Golgi bodies, cytoplasm, nucleus, nucleolus, nuclear
membrane, cell (plasma) membrane, mitochondria, rough
endoplasmic reticulum (RER), vacuole, cell wall, chloroplast,
smooth endoplasmic reticulum (SER).
***If needed, use your textbook and notes to help you.***
TURN OVER
Name ___________________________________
Mrs. Geithner-Marron (Bio 300)
Cells: The Basic Unit of Life Microscope Lab
Date _________
Period ________
6. Label the diagram of a typical “animal” cell with the following parts:
vacuole, lysosome, ribosomes, Golgi bodies, cytoplasm, nucleus,
nucleolus, nuclear membrane, cell (plasma) membrane,
mitochondria, smooth endoplasmic reticulum (SER), rough
endoplasmic reticulum (RER), centrioles.
***If needed, use your textbook and notes to help you.***