Download Cells: Living Machine Lab - Liberty Union High School District

Cells: Living Machine Lab
Name _________________________________________ Pd _____
Purpose
The purpose of this lab is to examine the basic structure of plant and animal cells.
Background
In this lab, you will be looking at several types of cells. Using a microscope, you will observe:
1) epithelial cells from an onion bulb.
2) cells from a living plant, Egerea densa. E. densa is a water plant found submerged in water.
3) animal cells from a familiar source: the cells lining the inside of your mouth.
Materials
E. densa, onion, microscope, Lugol’s iodine, water, microscope slides, cover slips, toothpicks
Safety Information
Be careful when working with stains!
Be careful of broken glass when working with microscope slides.
Procedure
Onion Cells
1. Carefully peel off a thin layer of red onion (containing a layer of cells called the epidermis).
2. Put a drop of water on a clean slide.
3. Lay the onion layer on top of the water and flatten it out using a toothpick. Smooth out any wrinkles.
4. Find the cells on 4x (low power).
5. Switch to medium (10x) and then high (40x) power.
6. Identify the parts of the onion cells. Find the nucleus, nucleolus, cytoplasm, and cell wall.
7. Draw several onion cells as they appear under low power (4x).
8. Draw several onion cells as they appear under high power (40x). Label the following parts: nucleus,
nucleolus, cytoplasm, and cell wall.
E. densa
1. Obtain an E. densa leaf and carefully place it on a microscope slide.
2. Add one drop of water to the slide, then add the cover slip.
3. Place the slide on the stage of the microscope.
4. Identify the cells wall and chloroplasts. You may see chloroplasts moving!
5. Draw several E. densa cells as they appear under low power (4x).
6. Draw several onion cells as they appear under high power (40x). Label the following parts: chloroplasts,
cytoplasm, and cell wall.
Animal Cells
1. Obtain a clean slide and cover slip.
2. Take the flat side of a toothpick and lightly scrape the inside of your cheek.
3. Take the toothpick and rub it flatly on the clean slide.
4. Add one drop of iodine and then add the cover slip.
5. Examine the cells with the microscope.
6. Try to identify the parts of the cell. Look for the nucleus, cytoplasm, and cell membrane.
7. Draw several cheek cells as they appear under low power (4x)
8. Draw several cheek cells as they appear under high power (40x). Label the following parts: nucleus,
cytoplasm, and cell membrane.
Name:
Period:
Observations and Data
Drawings of Cells
Directions: Draw 5 or more cells under low and high power and label the following parts: nucleus,
cytoplasm, cell membrane, cell wall, and chloroplasts.
Onion Cells: low power (4x)
Onion Cells: high power (40x)
E. densa Cells: low power (4x)
E. densa Cells: high power (40x)
Cheek Cells: low power (4x)
Cheek Cells: high power (40x)
Analysis
1. Describe the shape of the
a. Onion cell ___________________________________________________________________
b. Elodea cell ___________________________________________________________________
c.
Cheek cell ___________________________________________________________________
2. Are the cells regular or irregular in shape? (meaning, do they all look the same or are some shaped differently)
a. Onion cell _________________________
c. Cheek cell __________________________
b. Elodea cell ________________________
3. What are the factors that might determine cell shape and size? _________________________________
______________________________________________________________________________________
4. What are the similarities between the onion cell and Elodea cell? ________________________________
______________________________________________________________________________________
5. What are the differences between the onion cell and Elodea cell? _______________________________
______________________________________________________________________________________
6. Compare and contrast the onion and cheek cell. _____________________________________________
______________________________________________________________________________________
7. Why was it was necessary to stain the cheek cell? ___________________________________________
______________________________________________________________________________________
8. Why didn’t we have to stain the Elodea cell? ________________________________________________
9. What structures are found in plant cells but not animal cells? ___________________________________
10. What features make plant and animal cells different from bacteria? _____________________________
______________________________________________________________________________________
Conclusion
Compare and contrast plant and animal cells using a Venn Diagram or 3-column chart.(Just plants, both, Just Animals)