TYPES OF CELLS LAB NAME ______________ DATE -------------- The Cell Theory states that all living organisms are made of cells. It was only after microscopes were developed and we were able to view the universality of cells that this theory was accepted. Although cells are the building block of all living organisms, different types of organisms have different types of cells. In this lab, you will be examining and comparing plant and animal. How to make a cork slide: https://www.youtube.com/watch?v=b-x3xqB.fil_QQ How to make a cheek slide: https://www.youtube.com/watch?v=PrX3h-AflZI A. PLANT CELLS: CORK Over 300 years ago, Robert Hooke looked at cork under a microscope. He saw little boxlike structures that he called cells. Cork does not contain living tissue and only contains a cell wall. By the 19th century, it was accepted that all living things are made of cells. Cells are all different sizes and shapes but they contain certain common structures. 1. Obtain a prepared cork slide. 2. Focus and observe under LOW POWER (100x). Sketch carefully in detail using pencil. It should look exactly like the field of view. 3. Then turn to HIGH POWER (400X) and re-focus. Sketch carefully in detail using pencil. It should look exactly like the field of view. r� 'I � ----- / ( \ �___...-- ......_ CELL WALL \"------· 100X Low Power a. 400X High Power Draw an arrow from the word CELL WALL to each sketch. b. There are no other cell structures visible because the cork is not living. What happened to the other structures in this dead tissue? _______________________________ c. Why does cork have a cell wall? What kind of cell is it and where does it come from? _________ A. Pl.ANT CELLS: ONION CELLS 1. Obtain a new, clean slide. 2. Using forceps remove the thin inner lining from a section of onion bulb and place flat. 3. Stain with a drop of lugol's Iodine before dropping the cover slip on. 4. Wipe edges of any excess liquid being careful not to suck the liquid out from under the cover. 6. Focus and observe under low power in the microscope and scan the slide. Once you find a good specimen of cells then turn to higher power and observe further. 7. Make a nice, clear drawing of the cells in the space below and label any identifiable structures. LABEL the cell wall, cell membrane, cytoplasm, and nucleus. Use colored pencils to complete your drawing. Low Power 100X High Power 4OOX C. Pl.ANT CELLS: ELODEA CELLS 1. Place a drop of water on a new, clean slide. 2. Using forceps remove a bright green leaf from an Elodea plant. 3. Place the leaf in the drop of water on your slide. 4. Do not stain. Cover the leaf with a cover slip. 5. Observe under low power in the microscope and scan the slide. Once you find a good specimen of cells then turn to higher power and observe further. 6. Make a nice, clear drawing of the cells in the space below and label any identifiable structures. Be sure to label the cell wall, cell membrane, cytoplasm, chloroplasts, and central vacuole. Use colored pencils to complete your drawing. 7. Now focus on one or two cells and watch the cells carefully to see if you see movement within the cells. LOW POWER 100X HIGH POWER 4OOX ANALYSIS OF PLANT CELLS: Refer to parts A, B, C to answer these questions d. Do all the plant cells that you viewed have chloroplasts? _________ e. Why would some plant cells not have chloroplasts? Explain. (think about where the onion and elodea plants arefound) ---------------------------- f. What is the function of chloroplasts? _______________________ g. What color are chloroplasts ? __________________________ h. Look at where the chloroplasts are in the cell. What pushes them to this location? ________ i. What is the general shape of plant cells? _______________________ j. Explain which cell structure causes this shape. _____________________ k. Do plant cells have a cell membrane? ________________________ I. Why was the cell membrane not easy to see on the plant cells? Where is it located? ________ m. Why didn't we stain the Elodea leaf? _________________________ D. ANIMAi. CELLS: HUMAN CHEEK CELLS 1. Place a drop of water on a new, clean slide. 2. Take a toothpick and gently rub it against the inside of your cheek. Do NOT use force, you are dislodging loose cells, not gouging a hole in your cheek. 3. Stir the water on your slide with the end of the toothpick that you rubbed in your mouth. This will transfer the cells onto the slide. 4. Place one drop of methylene blue stain in the drop of water on your slide. Be careful, methylene blue will stain your hands and clothing. 5. Let this stain stay on the slide for one minute and then place a cover slip on the slide. 6. Observe under low power in the microscope and scan the slide. Once you find a good specimen of single cells then turn to higher power and observe further. 7. Make a nice, clear drawing of the cells in the space below and label any identifiable structures. Be sure to find the cell membrane, cytoplasm, and nucleus. Use a colored pencil to complete you drawing. Low Power 100X High Power 4OOX ANALYSIS: n. What cell structures or organelles were visible in the plant or animal cells? animal: ___________________________________ plant: ___________________________________ o. List four more cell structures which must be in those cells even though you could not see them: animal: _________ plant: ___________, __________, ------------J---------p. Of the cell structures that you saw, which two cell structures occurred only in plants? q. Why are stains, like methylene blue and iodine, used when viewing cells? r. Why are the structures within plant and animal cells called organelles? s. Which life processes do cell organelles perform? t. You are given an unknown cell to identify as plant or animal In a paragraph, describe how you would be able to use a compound microscope to identify what type of cell it is.
