Download Purpose: You will observe human cheek cells and onion cells and

Comparing Plant and Animal Cells
Name: _____________
Block: _____________
Purpose:
To observe and compare the similarities and differences
between animal cells and plant cells by observing human cheek cells compared
to onion cells. You will gain experience recognizing visible cell structures,
making scientific drawings of your observations and calculating actual size.
PART A: Preparing a Wet Mount Slide of Plant Cells
1. Pull the onion slice apart
2. Pull off a thin piece of onion skin
3. Place the onion skin piece on the centre of the slide. Add a drop of
water, one drop of methylene blue and then the cover slip
4. Observe and draw the stained onion skin cell on medium or high power
(F.O.V = 1.75 mm on med and F.O.V. = 0.43 mm on high power)
5. Label the structures listed below and complete the questions
Title: ______________________
Power:______x
Total Magnification: ________
Scientific Drawing
Label the following structures:
Cell Wall, Cell Membrane
Cytoplasm, Nucleus
Calculate Aprox. Size of 1 Cell in µm:
PART B: Preparing a Wet Mount Slide of Cheek Cells
1. Gently rub the inside of your cheek with a rounded end of a wooden
splint. Smear the material over the center of a clean slide. Discard
the splint into the garbage can.
2. Add one drop of water to the slide, one drop of methylene blue and
then add your cover slip.
3. Find the cheek cellsl on low… they will look like very tiny dots on low.
As you move up in magnification, the cheek cells will start to resemble
a fried egg!
4. Observe and draw the cheek cell at medium or high power. Label the
structures listed below and calculate aprox. actual size of 1 cell.
(F.O.V = 1.75 mm on med and F.O.V. = 0.43 mm on high power)
5. Discard your cover slip in the broken glass container. Wash your slide
and hands with soap and water.
Title: ______________________
Power:______x
Total Magnification: ________
Scientific Drawing
Label the following structures:
Cytoplasm, Cell Membrane
Cell Wall, Nucleus
Calculate Aprox. Size of 1 Cell in µm:
Discussion Questions- see Chap 3 in the text for help! Pg 46-63
1. The Cell Theory is said to form the basic framework that biologists use to
understand living things. In your own words what are the 3 main points?
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2. Name one key organelle that you would expect the ONION cell to have but
that would NOT be found in an animal cell. Why do you think a plant like the
onion specifically need this organelle yet an animal does not?
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3. a)Name the special process used to make chemical energy in an animal cell.
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b) Write the word equation for this process.
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4.a) How can you recognize the nucleus in the cheek cells? Describe it.
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b) Name the category of cells that DO NOT have a nucleus. Give one specific
example of such an organism.
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Discussion cont…
Critical Thinking Questions
5. Would you expect the cell from the ONION SKIN to have a small or large
vacuole? Explain why.
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6.a) What type of microscope do you think you would need to see the nuclear
envelope and the nucleolus? Explain why you’d need this type of microscope.
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b) Describe what you would expect to see if you had access to this
microscope._____________________________________________________
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7. How does the outer boundary of a cheek cell differ from the outer
boundary of an onion cell? What do they both have in common? Be very
specific in terms of structure and function.
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Conclusion:
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Avoid using “I”, “We”, “my” etc. Write in 3rd person / passive voice
Re-state the purpose of this lab
Summarize the big ideas that were reinforced / demonstrated
Suggest scientific error
Suggests scientific ways to improve and/or expand this lab in the future
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PLANT & ANIMAL CELL LAB REPORT CRITERIA
Beginning
Developing
Accomplished
Name: _________________
Block: _____
Date: __________________
Exemplary
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Scientific
Drawings
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Discussion
Questions
(Weighted X2)
Conclusion
In Pencil
Detailed
Accurate
Includes slide title
Includes correct power &
total magnification
Includes all Labels
Drawn to scale
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Uses full sentences
All Qs Fully Completed
Shows all work
Includes all units
Answers in micrometers
Clear & Accurate answers
High Level of
Understanding Shown
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Uses full sentences
Addresses purpose
Written in 3rd person
Clearly & Accurately
Sums up big ideas
Detailed yet concise
Addresses Scientific
Sources of Error
Makes Scientific
suggestions/improvement
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Coached by: __________________
What’s Working:
What’s Next: