Name: _______________________________________ Date: _______________ Period: _________ Comparing Plant & Animal Cells Purpose: Students will observe plant and animal cells using a light microscope and be able to compare and contrast the cells. Part A: Cork Cells 1. Observe the prepared cork slide under a microscope. 2. Diagram under high power in the Data & Observations Section of the lab report. Identify the cell walls in your diagram. Part B: Onion Cells 3. Put a drop of water in the center of a slide. 4. Using forceps, carefully peel the thin inner skin from the inside layer of an onion. Tear off a piece smaller than the cover slip. 5. Place the onion skin on top of the drop of water making sure there are no folds in the skin. 6. Place one drop of iodine solution on the onion. 7. Gently lower a cover slip over the skin. 8. Diagram under medium power. Identify the cell walls in your diagram. 9. Clean and dry your slide and cover slip. Part C: Cheek Cells 10. Place one drop of iodine in the center of a slide. 11. Gently scrape the inside of your cheek with the flat end of a toothpick. 12. Stir the saliva end of the toothpick into the drop of iodine solution on the slide. 13. Throw away the toothpick. 14. Gently lower the cover slip onto the slide. 15. Diagram under high power. Identify the nucleus in your drawings. Part D: Elodea Cells 16. Place one drop of water in the center of a slide. 17. Place one elodea leaf in the drop of water. 18. Cover with a cover slip. 19. Diagram under high power. Identify the cell wall, chloroplasts, vacuole and nucleus. 1. Relate the parts of the cell to your school. Match each structure’s function with the corresponding school area or part. 1) ______________ Cell Wall a. Doors and windows 2) ______________ Mitochondria b. Electrical room 3) ______________ Cell membrane c. Cafeteria 4) ______________ Chloroplast d. Principal’s office 5) ______________ Nucleus e. Bricks of the building 2. What do you call the small units in the cork that can be seen under high power? ___________________ 1) Do these units appear filled or empty? _________________________________ 2) What evidence do you have that it is produced by a plant? ______________________________________ _____________________________________________________________________________________________________________ 3. Why is the iodine necessary for the onion and cheek cell slides? ______________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________ 4. Explain why chloroplasts were visible in the elodea cells but not the onion cells? ______________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________ 5. What evidence did you see in the cheek cells to prove that it is made up of animal cells? ______________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________ Data & Observations: Cork Cells ___________________X (Identify cell wall) Cheek Cells ___________________X (Identify cell membrane & nucleus) Onion Cells ___________________X (Identify cell wall) Elodea Cells ___________________X (Identify cell wall, chloroplasts, & nucleus) Questions & Conclusions: 6. Mark each column below with a check mark for the cell or cells the word or phrase describe. More than one choice may be used. Cork Onion Cheek Elodea round or circular in shape rectangular or brick-­‐like in shape cell wall no cell wall cytoplasm nucleus chloroplasts cell membrane an animal cell a plant cell