Download Lab Activity: Plant/Animal Cells Through this lab activity you wil

Name:__________________________
Period:______ Date:__________
Lab Activity: Plant/Animal Cells
Through this lab activity you will learn…
 Microscope skills.
 How plant cells resemble animal cells.
 How plant cells differ from animal cells and to what degree they differ.
Onion Cells
Background on the onion epidermis: Onions are very dead-looking when you buy them at the grocery store. In
reality an onion bulb is full of living cells that can grow into roots, stems and leaves when the bulb is planted
(or perhaps stored too long under slightly moist conditions). You will be examining the cells found making up
the outer skin of the bulb – the epidermis.
1. As per lab instructions, peel the thin layer of cells from the concave surface of your scale – portion of the
onion bulb.
2. A transparent, paper-thin layer of cells (epidermis) should easily be removed.
3. Place this layer in a drop of water on your slide in such a manner that the innermost surface of the “skin” of
cells is against the glass slide.
4. With a razor blade trim the “skin” so that it is smaller than the cover slip. Use a teasing needle to flatten the
“skin”.
5. Place the coverslip over the skin as instructed by the teacher. Do not press on the cover slip once it is placed!
6. Focus under low power then move up to high power to make your observations.
7. Now add a drop of iodine to the edge of the cover slip and, using a piece of paper towel, draw the stain across
the specimen. Be careful not to get iodine on anything you don’t want to remain the color of this stain.
8. Draw and label the cell after it has been stained.
Title:
Analysis Questions:
1. What is the general shape of these cells?
2. Explain how you can tell these are plant cells?
3. After you added iodine –
can you see any cellular structures better now than before? Explain.
4. What is the shape of the nucleus & where is it located in the cell?
5. Can you see any structures inside the nucleus? _________
On average, how many of these structures can you see in the nucleus?
6. Where does the onion cell store most of its water?
7. How does this relate to nucleus position in the cell?
Magnification:
Label your picture!
Cheek Cells:
You learned in the onion cell lab that the EPIDERMAL CELLS of an onion are flat. Parts of animal cells are
also covered with an EPIDERMIS.
In this lab you are going to look at your own epidermal cells.
1. Place a drop of water on a clean slide.
2. With the broad end of a toothpick, gently scrape the inside lining of your check and deposit it into the water
by rolling the toothpick.
3. Stir the water.
4. Add a small drop of iodine into the water. Cover with a coverslip.
5. Observe under high power. You may find some cells creased or piled on top off one another, or some may be
broken. Find one or two cells that are clearly visible, and isolated from the others. Title:
Draw and label a few cheek cells.
Magnification:
Label your picture!
Analysis Questions:
1. How does the external surface and covering of the cheek cells compare with the walls of the plant cells?
2. Are these cells cubical, spherical, or flat?___________
3. Think about eating. Feel the inside of your mouth with your tongue. How does the flatness of the cell relate to
the cell’s function.
Elodea Cells:
Background info: One of the most conspicuous features of our world is green foliage. Although few sights have
more aesthetic appeal than many shades of green in the forest and fields, we usually take this greenness for
granted, without pausing to ask why plants are green.
For your first detailed observation of living green plant cells, you will use the leaves of elodea, a common
flowering plant which is widely distributed in fresh water lakes, ponds, etc. You find it frequently in pet shops
and variety stores where it is sold for planting aquaria.
The scientific name for elodea is Anacharis.
1. Take one plant from a finger bowl and break off one of the younger leaves near the tip of the branch.
2. Place it bottom-side-up in a drop of water on a clean slide and put on a coverslip.
3. Look at the plant under low power.
4. Observe the plant on high power and draw and label a few cells.
Analysis Questions:
1. What are the small green bodies inside of each cell? _______________
2. Where exactly are these green organelles located in the cell. Draw a picture and label.
3. Describe the movement of the chloroplasts throughout the cell. Be as specific as possible- include direction,
pattern of movement, etc.. If you do not see the chloroplasts moving, use the teacher’s example.
4. Form a hypothesis that accounts for the location of the chloroplasts within a cell. This is an educated guess.
5. Chloroplasts cannot move on their own. Give an educated guess as to how they are moving.
6. What is the difference between the onion cells and the elodea cells you viewed under the microscope. (Could
you tell the difference between them if you saw them on a microscope?)
7. In regards to the onion as a plant and the elodea as a plant- what is the difference in function between the
onion cells you observed versus the elodea cells you observed?
Table: In the table, put a “yes” in the box if the cell contained the organelle listed below and a “no” if it does
not contain it. You did not have to actually see the organelle for the cell to have it.
Onion
Cell Wall
Cell Membrane
Nucleus
Cytoplasm
Large Water Vacuole
Chloroplasts
Elodea
Cheek
Summary Questions:
1. Name 3 differences between plant and animal cells.
1.
2.
3.
2. Why do both plant and animal cells have mitochondria in their cells but only plant cells can have
chloroplasts? (Hint: relate to the function of each organelle and that animals are consumers and plants are
producers)
3. Use your textbook as a reference to label the cell diagram below with the following choices: plant cell,
animal cell, plasma membrane, chloroplast, small vacuole, large water vacuole, cell wall.
If Time Permits:
Ask your teacher for additional slide of cells. For each slide:
 Draw the cells as they appear under the microscope. Name the cells you are viewing. Are they plant or
animal cells? Indicate the magnification under which they are viewed and label all organelles you can
identify. Write a brief description of what you see.
Title:
Magnification:
Label your picture!
Title:
Magnification:
Label your picture!
Description:
Description: