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? _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ ________________________________________________________ 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? ________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ 3. a)Name the special process used to make chemical energy in an animal cell. _______________________________________________________ b) Write the word equation for this process. _______________________________________________________ 4.a) How can you recognize the nucleus in the cheek cells? Describe it. ________________________________________________________ b) Name the category of cells that DO NOT have a nucleus. Give one specific example of such an organism. ______________________________________________________________ _____________________________________________________________ Discussion cont… Critical Thinking Questions 5. Would you expect the cell from the ONION SKIN to have a small or large vacuole? Explain why. _________________________________________________________ _________________________________________________________ _________________________________________________________ 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. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ b) Describe what you would expect to see if you had access to this microscope._____________________________________________________ ______________________________________________________________ ______________________________________________________________ 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. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ _________________________________________________________ _________________________________________________________ Conclusion: 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 _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ PLANT & ANIMAL CELL LAB REPORT CRITERIA Beginning Developing Accomplished Name: _________________ Block: _____ Date: __________________ Exemplary Scientific Drawings Discussion Questions (Weighted X2) Conclusion In Pencil Detailed Accurate Includes slide title Includes correct power & total magnification Includes all Labels Drawn to scale Uses full sentences All Qs Fully Completed Shows all work Includes all units Answers in micrometers Clear & Accurate answers High Level of Understanding Shown 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 Coached by: __________________ What’s Working: What’s Next: