Plant vs. Animal Cell Structures
Purpose:



To observe animal cell structures which are not visible with the light microscope
To observe plant cells
To compare structures seen in plant and animal cells
Materials: Microviewer, slide and booklet, slide, cover slip, iodine, onion, elodea
Procedure:
Part I. Elodea Cells
1. Obtain a microscope, plug it in, and put the low power objective into place.
2. Prepare a wet mount slide of an elodea leaf. Focus it under low power, then move it to high
power.
3. In number 1 of your data sheet, draw what you see. Be sure to label the cell wall, the cell
membrane, and the chloroplasts.
4. Throw out the leaf, and rinse your cover slip and slide. You may reuse them for the next part.
Part II. Onion Cells
1. Remove a very thin layer of skin from an onion provided by your teacher.
2. Put the onion on a slide, and make a wet mount slide.
3. Focus it under low power, then under high power.
4. In number 2 of your data sheet, draw what you see and label any cell structures seen.
5. Bring your onion slide up to the front of the room. Remove the cover slip, and add a drop of
iodine to the onion. Put your cover slip back on. Be very careful with iodine--it can stain
your clothes!!
6. Focus the onion slide under low power, then move it to high power.
7. In number 3 of your data sheet, draw what you see and label the cell structures seen.
8. Carefully clean the slide and cover slip. Throw out the onion skin. Place the slide and cover
slip on the paper towel at the middle lab table to dry.
Part II. Animal cells
1. Use the microviewer to observe the structures of the animal cell which are not visible with the
light microscope.
2. On your data sheet, for each slide specified, draw what you see, and label each structure.
Refer to the reading that goes along with each slide to help in labeling your diagrams.
Data:
Part I.
1. Elodea leaf
Part II.
2. Onion with water only
3. Onion with iodine
Part III.
Slide 1: This slide shows many cells from a human oil gland. Draw one cell, and label the cell
membrane, nucleus, and cytoplasm.
Slide 2: Draw and label the endoplasmic reticulum, ribosomes, mitochondrion, nucleus, and
nucleolus.
Slide 4: Draw and label the golgi body and vacuole.
Slide 5: Draw the mitochondrion (actually half of one) shown. Use your notes to label the inner
membrane, outer membrane, cristae, and matrix (booklet does not help with these labels).
Slide 6: Draw the centriole. Use your notes to circle and label 1 microtubule triplet (booklet
does not help with these labels).
Slide 7: Draw and label the chromosomes.
Analysis questions: Refer to your notes on cell structures and the reading in the booklet to
answer the following questions.
1. What cell structures were you able to see in the elodea cells?
2. What cell structures were you able to see in the onion cells with just water?
3. When the iodine was added to the onion, what cell structures became stained and became
visible to you?
4. Why were chloroplasts visible in the elodea leaf, but not in the onion? What other parts of a
plant would contain cells without chloroplasts?
5. Notice the way the endoplasmic reticulum winds throughout the cell. How does this
arrangement help the ER to perform its job of transporting proteins in the cell? What other
structures inside the cell does the ER connect with?
6. How will the proteins made in the ribosomes found in the cytoplasm be used by the cell?
How does that differ from the proteins made in the ribosomes on the rough ER?
7. Once proteins are made on the smooth ER, they will travel to what structure to be processed?
8. Explain why gland cells would contain so many of the organelles named in # 7 (vs. muscle or
nerve cells which would not have as many of these organelles)?
9.
Many people confuse the golgi bodies and endoplasmic reticulum in the cell because they
look very similar. How can you tell them apart based on what you could see in slides 2 & 4?
10. Observe the mitochondrion. Notice the folds throughout the middle of the structure. What
are those folds called? What is the purpose of those folds? How do they affect the amount
of energy that is produced at the mitochondria?
11. What kinds of cells in your body would you expect to contain a lot of mitochondria? Why?
12. What structure is controlling all of the activities that occur within the cell?
13. The nuclear envelope has many small pores in it. What materials would pass through those
pores going into the nucleus? What materials would leave the nucleus?
14. What important information is found on the chromatin? What makes up chromatin? What
will that chromatin turn into prior to cell division?
15. If you were looking at a plant cell, how would you expect the vacuole to look in comparison
to how it looks in the animal cell? Why the difference between the vacuoles in the two types
of cells?
16. Whenever materials need to enter or leave the cell, through what structure(s) will they pass
in an animal cell? In a plant cell?
17. In which type of cells would you expect to see more lysosomes? Plant or animal cells?
Why?