* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Visualizing Cells Lab
Cell growth wikipedia , lookup
Cytokinesis wikipedia , lookup
Endomembrane system wikipedia , lookup
Extracellular matrix wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cell culture wikipedia , lookup
Cell encapsulation wikipedia , lookup
Tissue engineering wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Name _____________________________ Date ___________________ Block __________ Visualizing Cells Lab Purpose: In this lab you will be able to observe similarities and differences between animal and plant cells. Question: Are animal and plant cells the same? Observations: The two types of cells follow similar designs: both have a nucleus and cytoplasm containing various organelles and both are contained within a cell membrane. There are, however, three significant differences between animal and plant cells: 1. Plant cells are surrounded by a rigid cell wall outside the cell membrane. Animal cells do not have a cell wall. 2. Animal cells usually have a few small vacuoles, while mature plant cells usually contain only one large vacuole. 3. Plant cells contain organelles called plastids, with most noticeable being chloroplasts. Animal cells do not contain plastids. Hypothesis: Materials: Compound microscope Various animal and plant prepared slides Colored pencils Procedures: Part I. Animal Cells 1. Turn on the microscope. NOTE: Human cheek cells are prepared by scraping the inside of the mouth and then smearing the material onto a slide. 2. Place the human cheek cell prepared slide on the stage using the stage clips to keep it in place. 3. Using the 4X objective and the coarse adjustment knob, bring the specimen into focus. 4. Using the nosepiece holding the objectives, turn the objectives to the 10X objective and the fine adjustment know, bring the specimen into focus. 1. Note the shape of the cell and draw what you see. Label the cell membrane and nucleus, which should show as a darker stain and circular in the Observation & Data section of your lab. NOTE: You will probably notice many small objects on the slide with the cheek cells. These are some bacteria normally found in the mouth. Draw these as well. 5. Using the nosepiece holding the objectives, turn the objectives back to the 4X objective. 6. Use the coarse adjustment knob to bring the stage back down to the starting position. 7. Remove the human cheek cell slide and place it back in the slide box. NOTE: The Amphiuma is a salamander. The liver is an organ, which is made up of various types of tissue. A tissue is a group of cells of similar structure and function. An organ is a part of an organism having a definite structure and performing one or more specific functions. 8. Place the Amphiuma Liver Cell prepared slide on the stage using the stage clips to keep it in place. 9. Using the 4X objective and the coarse adjustment knob, bring the specimen into focus. 10. Using the nosepiece holding the objectives, turn the objectives to the 10X objective and the fine adjustment know, bring the specimen into focus. 2. Look at the large cells in the central portion of the liver away from the ducts and openings. You should be able to see a nucleus and cytoplasm in most of the cells. Draw what you see and label the cell membrane and nucleus in the Observation & Data section of your lab. 11. Describe the appearance of the cytoplasm. 12. Vacuoles are fluid-filled sacs found in the cytoplasm of cells. In a prepared slide, vacuoles usually appear as clear (unstained) areas in the cell. a. Do you see anything inside the liver cells that look like vacuoles? 13. Using the nosepiece holding the objectives, turn the objectives back to the 4X objective. 14. Use the coarse adjustment knob to bring the stage back down to the starting position. 15. Remove the Amphiuma Liver Cell slide and place it back in the slide box. Part II. Plant Cells NOTE: Cork comes from the bark of the cork oak tree. The cells that make up the bark die when they reach maturity. The material that remains, making what we call “cork,” is the cells walls of the bark cells. 1. Place the cork cell prepared slide on the stage using the stage clips to keep it in place. 2. Using the 4X objective and the coarse adjustment knob, bring the specimen into focus. 3. Using the nosepiece holding the objectives, turn the objectives to the 10X objective and the fine adjustment know, bring the specimen into focus. 4. Note the arrangement of the cells. Draw what you see and label the cell wall in the Observation & Data section of your lab. 5. How does the shape of the cork cell compare to that of the cheek cells and Amphiuma liver cells? 6. Using the nosepiece holding the objectives, turn the objectives back to the 4X objective. 7. Use the coarse adjustment knob to bring the stage back down to the starting position. 8. Remove the cork cell slide and place it back in the slide box. NOTE: The tissue on this next slide is the epidermis or “skin” that covers the scales of an onion bulb. 9. Place the Onion Bulb Epidermis Cell prepared slide on the stage using the stage clips to keep it in place. 10. Using the 4X objective and the coarse adjustment knob, bring the specimen into focus. 11. Using the nosepiece holding the objectives, turn the objectives to the 10X objective and the fine adjustment know, bring the specimen into focus. 12. Draw what you see and label the cell wall, cell membrane, and nucleus in the Observation & Data section of your lab. 13. How do the onion cells compare to the cheek cells? 14. What difference do you notice between this slide, which was prepared from living tissue, and the cork slide, which was prepared from dead tissue? 15. Using the nosepiece holding the objectives, turn the objectives back to the 4X objective. 16. Use the coarse adjustment knob to bring the stage back down to the starting position. 17. Remove the Onion Bulb Epidermis Cell slide and place it back in the slide box. NOTE: The material on this slide shows a thin slice through a leaf. A leaf is an organ of a plant containing several types of tissue (epidermis, mesophyll, xylem, and phloem). 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. Place the Privet Leaf Cells prepared slide on the stage using the stage clips to keep it in place. Using the 4X objective and the coarse adjustment knob, bring the specimen into focus. Examine the slide under low power. Look at the middle layers of the leaf away from the midvein. You should see that the top part is made up of rectangular cells packed closely together and the bottom part is made up of irregular-shaped cells that are loosely arranged. Using the nosepiece holding the objectives, turn the objectives to the 10X objective and the fine adjustment know, bring the specimen into focus. Examine them more closely. You should be able to see both the cytoplasm, which is stained, and vacuoles, which are clear regions inside the cells. Draw what you see and label the cytoplasm and vacuoles in the Observation & Data section of your lab. Would you describe the vacuoles as being small or large? Do you see more than one vacuole in any of the cells? Look again at the stained regions of the cells. You should be able to see a nucleus in many cells. You will also see that many of the cells have organelles that have been stained dark red or purple. These are chloroplasts (in living plants, chloroplasts are green because they contain the pigment chlorophyll). Draw and label the chloroplasts as well. Would you say there are a few or many chloroplasts in the cells? Do all plant cells have chloroplasts? Using the nosepiece holding the objectives, turn the objectives back to the 4X objective. Use the coarse adjustment knob to bring the stage back down to the starting position. Remove the Privet Leaf Cell slide and place it back in the slide box. Observation & Data: Shown is what you should be viewing for each slide. This will help you draw what you are seeing. Human Cheek Cells Amphiuma Liver Cells Cork Cells Onion Bulb Epidermis Privet Leaf Cells Conclusion: Be sure to reference the foldable on writing a lab report.