Download COMPARING PLANT AND ANIMAL CELLS

COMPARING PLANT AND ANIMAL CELLS
BACKGROUND INFORMATION
This laboratory is aimed to help students distinguish between plant and animal cells. Students will
have an opportunity to prepare a wet mount of a plant cell and have an opportunity to practice
their scientific drawing skills.
PART A: PLANT CELL (ONION)
PURPOSE:
 To prepare a wet mount of a plant cell and examine the distinguishing structure of this cell type
 To prepare an accurate scientific drawing of the plant cells observed
MATERIALS:
- Compound Light Microscope
- 1 Microscope Slide
- 1 Cover slip
- Onion peel
-
Iodine staining dye (Lugol’s)
Paper towel
Plastic, transparent ruler
PROCEDURE:
1. Obtain a compound light microscope and set it up on your lab bench
2. Use the plastic ruler to determine the diameter of the field of view under low power. Record
this measurement on your worksheet in Table 1: Microscope Measurements.
3. Use this value to calculate the diameter of the F.O.V in medium and high power. Record these
values in Table 1: Microscope Measurements
4. Obtain a microscope slide and cover slip, holding them by the edges so that you do not leave
fingerprints on them. Lay them on a clean, dry surface.
5. Obtain a piece of onion and carefully break it in two. The two pieces should be held together
by a thin membrane. Carefully peel away this thin outer skin.
6. Place the thin skin in the centre of the clean microscope slide. Try to lay it as flat as possible
(no wrinkles). Use a toothpick to flatten/straighten out the skin.
7. Prepare a wet mount of the onion skin using Iodine. Place 1-2 drops of Iodine onto the onion
skin.
8. Carefully slide the coverslip onto the prepared slide. Carefully lower the coverslip and press
the top gently to remove any excess air bubbles.
9. Place a paper towel on the edge of the cover slip that covers your specimen. The paper towel
will pull the iodine, so as to distribute the dye through the entire specimen.
10. Place the slide on the stage and observe the specimen under low power. Ensure that the arrow
located in the field is pointing on the cell you want to observe.
11. Without moving the stage, change objectives and observe the specimen under medium power
(focus only using the fine adjustment knob)
12. Switch to high power objective, draw and label what you see. Use the steps in drawing
biological diagrams.
13. When finished, return the revolving nosepiece to the low power objective. Turn off the light
source. Lower the stage and remove the slide from the stage.
14. Remove the coverslip and dispose of the thin skin in the garbage. Clean and dry the slide and
coverslip. Return them to their appropriate containers
15. Tidy up your lab bench and return the microscope to their proper holding area.
PART B: ANIMAL CELLS (CHEEK)
PURPOSE:
 To use the microviewer to view a prepared animal cell under high magnification
 To prepare an accurate scientific drawing of the animal cells observed
MATERIALS:
- 1 Microviewer Booklet – Cells of the Body OR online image
- Microviewer
PROCEDURE:
1. Obtain a microviewer booklet “Cells of the Body” and take out the microslide viewer located
inside the booklet
2. Obtain a microviewer from your station.
3. Place the microslide viewer through your microviewer.
4. Insert the numbered end through moving it from right to left.
5. View image number 1: Cheek cells. Note the magnification on the booklet for this slide.
Ensure this magnification is specified in your scientific drawing.
6. Draw and label what you see. Remember to look at your biological diagram checklist as a
reference.
OBSERVATIONS:
Refer to Student Worksheet
DATE: ________________________
NAME: ________________________________________________
STUDENT WORKSHEET: COMPARING PLANT AND ANIMAL CELLS
OBSERVATIONS:
Table 1: Microscope Measurements
OBJECTIVE
Low
Medium
High
PART A:
TOTAL MAGNIFICATION (Show Work)
PART B: