Cell Identification Lab Questions
Pre-lab Questions:
1. What are the main parts of a microscope? (use you book if needed)
2. What are the magnifications on the microscope?
3. What are the kinds or sizes of cells that will be viewed under the microscope?
4. What will a hair or hair follicle look like under the microscope & WHY?
5. What are the main parts of plant cells that can be viewed under a microscope?
6. What are the main parts of animal cells that can be viewed under a microscope?
7. Will the cells be affected by the glass slide, cover or toothpick & look different?
8. How will the plant & animal cells differ from each other?
9. How can you tell the difference between dust or dirt and a cell on the slide?
Introduction:
The cell is one of the most unique things to look at under a microscope. It is easy to view
certain parts of a cell, which are integral parts of cell function. In this lesson students
will see the cells of onions, hair and cheeks to view the different parts or organelles.
Materials:
Gather all the parts that are needed for the lab and bring them back to the table:
1. A piece of onion (will be cut by teacher), one hair (provided by student’s head) and
one cheek swab (provided by student’s mouth)
2. 2 glass slides
3. 2 slide slip covers
4. Microscope (plug in at front of table and turn it on)
5. 2 Toothpicks
6. Paper towels
7. Drop of water on 2 slides
8. Eyedropper of Bromothymol blue (teacher will bring to students)
9. Textbook for example of animal & plant cells
Lab Directions: Onion:
- Take a glass slide and put ONE drop of water on it,
- Peel the thinnest layer of onion off the piece given and lay flat on a glass slide,
- Place slip cover on top of onion VERY SLOWLY so no air bubbles are trapped,
- Add ONE drop of bromothymol blue to glass slide just next too slip cover,
- Use paper towel to pull bromothymol blue through onion by dabbing on opposite
side of bromothymol blue drop,
- Put glass slide under microscope once onion cell is blue,
- Turn microscope on and put on lowest magnification level,
- View onion cell structure and parts,
- Draw a picture and take notes of what is seen,
- Increase magnification to 2nd & 3rd level and see anything different,
- Compare notes and what is seen with lab partner.
Cheek & Hair Cell:
- Take a glass slide and put ONE drop of water on it,
- Take the toothpick and lightly scrape the inside of your mouth to gather cheek cells,
- Carefully smear/wipe cheek cells on glass slide,
- Place slip cover on top VERY SLOWLY so no air bubbles are trapped,
- Do NOT use any bromothymol blue,
- Put glass slide under microscope and look for cluster/group of cheek cells,
- For hair cell, no cell slide needed, look at follicle end at all three magnifications
- Turn microscope on and put on lowest magnification level,
- View cheek cell structure and parts,
- Draw a picture and take notes of what is seen for each cell,
- Increase magnification to 2nd & 3rd level and see anything different,
- Compare notes and what is seen with lab partner.
Things that should be identified:

The type of cell (prokaryotic/eukaryotic and animal/plant)

What organelles can be seen

Color, shape and size (relative to others) of organelles and cells

How is this cell similar or different from the others viewed?
Use the textbook for questions about the cell and its parts. After the group is done,
turn in individual lab reports with all the work and drawings completed. A full lab
write up will be required for this laboratory. Be sure to include tables, notes,
drawings, etc. Summarize what was found during the lab and any interesting facts
about the cells.
Post-lab Questions:
1. What was the most interesting thing viewed under the microscope?
2. What were the most obvious differences between the cells?
3. What were the similarities between the cells?
4. How long did it take for the bromothymol blue to stain the onion cell?
5. How many and which parts or organelles from each cell could be seen?
6. Did anything go wrong during the lab? What parts of the lab went well?
Information Table
Describe the cells that were observed. Include all observations:
Cell
Size
Drawings of cells:
Shape
Color
Organelles
Similarities
Differences