Name ___________________________________ Mrs. Geithner-Marron (Bio 300) Cells: The Basic Unit of Life Microscope Lab Date _________ Period ________ Materials microscope prepared slide of cork slides iodine stain in dropper bottle coverslips methylene blue stain in water dropper bottle onion prepared slide of frog blood Elodea toothpick Introduction When different types of cells are viewed under a microscope, different cell parts can be seen. Certain living cells are best for showing parts like a nucleus or cell membrane. Once-living (preserved) cells are best for showing parts such as a cell wall. Cells from producer organisms (plants) will show parts such as chloroplasts and cell walls. Most consumer organisms (such as animals) have cells that do not have these parts, although fungi have cell walls. We will not view fungi in this lab. In this investigation, you will: observe a variety of living and once living materials under the microscope. study and locate under the microscope six specific cell parts (cell wall, cell membrane, cytoplasm, nucleus, nucleolus, and chloroplasts). compare the cell parts found in plant and animal cells. Name ___________________________________ Mrs. Geithner-Marron (Bio 300) Cells: The Basic Unit of Life Microscope Lab Date _________ Period ________ Part 1: The Cell Wall Cork cells are excellent for studying a cell part common to all plant cells. This part is the cell wall. In a cork cell, the cell wall is easily visible. The cork is no longer living. The cell wall remains as the only evidence of once living materials. 1. Obtain a very thin slice of cork and prepare a wet mount as shown to the right. 2. Locate and examine the cork under low power. 3. Switch carefully (while looking from the side at stage level) to high power and refocus using the fine-adjustment knob. 4. Draw several cork cells as they appear under high power. a. Be sure to draw your cells neatly, accurately, and as detailed as possible. Your drawing should look like what you see, not just some random line, dots, etc. 5. Label the cell wall. Analysis, Part 1: Answer the following questions. 1. Is the cork you viewed alive? ______________________________________________ 2. What are the small “boxes” that you (like Robert Hooke) saw in the cork called? ________ 3. Are these “boxes” you looked at filled with living material or are they empty? __________ 4. What part is all that remains of the cell? _____________________________________ 5. Is cork part of a plant or animal? ___________________________________________ 6. Do animal cells have cell walls? _____________________________________________ 7. The cell wall is made up of a carbohydrate called ________________________________ Name ___________________________________ Mrs. Geithner-Marron (Bio 300) Cells: The Basic Unit of Life Microscope Lab Date _________ Period ________ Part 2: The Cell Membrane and Cytoplasm Human cheek cells may be used for viewing the cell membrane and cytoplasm. A cell membrane is a thin outer boundary which surrounds the cell and separates it from neighboring cells. Cytoplasm is the jelly-like inner portion of the cell. 1. Use the pictures to the right as a guide when preparing your slide. 2. Place a drop of methylene blue stain in the center of a slide. (Picture A) 3. Gently rub the inside of your cheek with the end of a toothpick. (Picture B) a. You will not be able to see anything on the toothpick when you remove it from your mouth. 4. Dip the toothpick into the stain on the slide and gently mix once or twice. (Picture C). 5. Add a coverslip over the stain. 6. Locate and examine the cheek cells under low power. Try to locate and examine cells that are separated from each other rather than those that are clumped together. 7. Switch carefully (while looking from the side at stage level) to high power and refocus using the fine-adjustment knob. 8. Draw several cheek cells as they appear under high power. a. Be sure to draw your cells neatly, accurately, and as detailed as possible. Your drawing should look like what you see, not just some random line, dots, etc. 9. Label the cell membrane and cytoplasm. Name ___________________________________ Mrs. Geithner-Marron (Bio 300) Cells: The Basic Unit of Life Microscope Lab Date _________ Period ________ Analysis, Part 2: Answer the following questions. 1. Describe the shape of a cheek cell. __________________________________________ 2. Are cheek cells found in plants or animals? ____________________________________ 3. Do cheek cells have cell walls? _______ Why/why not? ___________________________ 4. Are cheek cells alive (while they are in your mouth)? _____________________________ 5. Where is the cell membrane located? ________________________________________ 6. What is the function (job) of the cell membrane? _______________________________ 7. Where is the cytoplasm located? ___________________________________________ 8. What does cytoplasm look like (without stain)? (Remember: The color is due to the methylene blue stain.) ___________________________________________________ 9. What are the two main jobs of the cytoplasm? ________________________________ 10. Why did we add stain to the cheek cells? _____________________________________ Name ___________________________________ Mrs. Geithner-Marron (Bio 300) Cells: The Basic Unit of Life Microscope Lab Date _________ Period ________ Part 3: The Nucleus, Nucleolus, and Nuclear Membrane Onion cells may be used to show a cell’s nucleus and nucleolus. These two structures appear within most living cells. There may be several nucleoli (plural of nucleolus) appearing as tiny dots within each cell’s nucleus. The nucleus will appear as a round structure inside each cell. Use the pictures to the right as a guide when preparing your slide. 1. Obtain a piece of onion and snap it in half as shown to the right. (Picture A) 2. Use your fingernail to peel off a thin layer of onion tissue (from the side that is curved inward). (This layer will look almost like tissue paper.) (Picture B) 3. Place one thin onion layer onto the slide. Make sure to uncurl or unfold any overlapped portion of the onion so that the tissue lays flat. 4. Place a drop or two of iodine stain on the onion tissue. a. CAUTION: If iodine spillage occurs, notify the teacher immediately. Iodine can stain your skin (rinse thoroughly if it gets on your skin). Iodine can also stain clothes. 5. Add a coverslip over the stain. a. Tap the coverslip gently with the eraser end of your pencil to drive out any air bubbles if needed. 6. Locate and examine the onion cells under low power. Note the brick-wall appearance of the walls separating the cells. 7. Switch carefully (while looking from the side at stage level) to high power and refocus using the fine-adjustment knob. 8. Locate a small round structure, the nucleus, within each cell. You will probably need to focus up and down to get the best view of the nucleus. 9. Also, observe the tiny dots within the nucleus. These are the nucleoli (plural of nucleolus). 10. Also observe the outer edge of the nucleus. This thin covering is called the nuclear membrane. Name ___________________________________ Mrs. Geithner-Marron (Bio 300) Cells: The Basic Unit of Life Microscope Lab Date _________ Period ________ 11. Draw a SINGLE onion cell as it appears under high power. a. Be sure to draw your cells neatly, accurately, and as detailed as possible. Your drawing should look like what you see, not just some random line, dots, etc. 12. Label the cell wall, nucleus, nucleolus, and nuclear membrane. Analysis, Part 3: Answer the following questions. 1. Describe the shape of an onion cell. __________________________________________ 2. Are onion cells found in plants or animals? _____________________________________ 3. Do onion cells have cell walls? ________Why/why not? ____________________________ 4. Describe the shape of the nucleus in the onion cell. ______________________________ 5. The nucleus is found “floating” in the ________________________________ of the cell. 6. What is the function (job) of the nucleus? ____________________________________ 7. Describe the shape of the nucleolus in the onion cell. _____________________________ 8. The nucleolus is found within the ___________________________________ of the cell. 9. What is the function (job) of the nucleolus? ___________________________________ 10. What structure separates the inside of the nucleus from the cytoplasm within the cell? ____________________________________________________________________ 11. Why did we add stain to the onion cells? _____________________________________ Name ___________________________________ Mrs. Geithner-Marron (Bio 300) Cells: The Basic Unit of Life Microscope Lab Date _________ Period ________ Part 4: Chloroplasts Another cell part found in the cells of many producers is the green chloroplasts. Elodea, a common water plant, shows these important structures clearly. 1. Obtain a leaflet of an Elodea plant, and prepare a wet mount as shown to the right. 2. Locate and examine the Elodea under low power. 3. Switch carefully (while looking from the side at stage level) to high power and refocus using the fine-adjustment knob. 4. Note the small green organelles inside each cell. These are the chloroplasts. Movement of the chloroplasts within the cell (cyclosis) often can be observed. Attempt to locate moving chloroplasts. 5. Draw a SINGLE Elodea cell as it appears under high power. a. Be sure to draw your cells neatly, accurately, and as detailed as possible. Your drawing should look like what you see, not just some random line, dots, etc. 6. Label the cell wall and chloroplasts. Name ___________________________________ Mrs. Geithner-Marron (Bio 300) Cells: The Basic Unit of Life Microscope Lab Date _________ Period ________ Analysis, Part 4: Answer the following questions. 1. Describe the shape of an Elodea cell. ________________________________________ 2. Is Elodea a plant or animal? _______________________________________________ 3. Do Elodea cells have cell walls? _______Why/why not? ___________________________ 4. What color are the chloroplasts? ___________________________________________ 5. What shape are the chloroplasts? ___________________________________________ 6. The chloroplasts are found “floating” in the ___________________________ of the cell. 7. What is the function (job) of the chloroplasts? _________________________________ 8. Are chloroplasts usually found in the cells of consumers? _______________Why/why not? ____________________________________________________________________ Name ___________________________________ Mrs. Geithner-Marron (Bio 300) Cells: The Basic Unit of Life Microscope Lab Date _________ Period ________ Part 5: Plant or Animal Cell? 1. Obtain a prepared slide of frog blood. 2. Locate and examine the frog blood cells under low power. Note that the colors you see are not natural. Stains have been added to these cells to make viewing easier. 3. Switch carefully (while looking from the side at stage level) to high power and refocus using the fine-adjustment knob. 4. Draw several frog blood cells as they appear under high power. a. Be sure to draw your cells neatly, accurately, and as detailed as possible. Your drawing should look like what you see, not just some random line, dots, etc. 5. Label the cell wall, cell membrane, cytoplasm, chloroplasts, and nucleus ONLY if these parts are present! Not all of these parts may be seen in frog blood. Analysis, Part 5: Answer the following questions. 1. Describe the shape of frog blood cells. _______________________________________ 2. Do frog blood cells have cell walls? _______Why/why not? _________________________ 3. Do frog blood cells have chloroplasts? ________ Explain your reasoning. ________________ ______________________________________________________________________ 4. What structure separates the inside of the frog blood cell from its environment? ____________________________________________________________________ 5. What is the name of the dark, oval-shaped part found in the center of the frog blood cell? ____________________________________________________________________ Name ___________________________________ Mrs. Geithner-Marron (Bio 300) Cells: The Basic Unit of Life Microscope Lab Date _________ Period ________ Analysis, General: Answer the following questions. 1. Complete the chart below. Place a check mark in the boxes to indicate if a structure is found in a plant cell or animal cell (IN GENERAL, not just based on what you saw in this lab). If the structure is NOT found in that type a cell, put an X in the box. 2. Cork, onion, and Elodea cells are all ____________________________ cells. 3. Cheek and frog blood cells are ________________________________ cells. 4. Name TWO parts that animal cells have that plant cells don’t have. ____________________ ______________________________________________________________________ 5. Name TWO parts that plant cells have that animal cells don’t have. ___________________ ______________________________________________________________________ 6. Name at least FOUR parts that plant and animals cells have in common? ________________ ________________________________________________________________ Name ___________________________________ Mrs. Geithner-Marron (Bio 300) Cells: The Basic Unit of Life Microscope Lab Date _________ Period ________ 7. Label the diagram of a typical “plant” cell with the following parts: ribosomes, Golgi bodies, cytoplasm, nucleus, nucleolus, nuclear membrane, cell (plasma) membrane, mitochondria, rough endoplasmic reticulum (RER), vacuole, cell wall, chloroplast, smooth endoplasmic reticulum (SER). ***If needed, use your textbook and notes to help you.*** TURN OVER Name ___________________________________ Mrs. Geithner-Marron (Bio 300) Cells: The Basic Unit of Life Microscope Lab Date _________ Period ________ 8. Label the diagram of a typical “animal” cell with the following parts: vacuole, lysosome, ribosomes, Golgi bodies, cytoplasm, nucleus, nucleolus, nuclear membrane, cell (plasma) membrane, mitochondria, smooth endoplasmic reticulum (SER), rough endoplasmic reticulum (RER), centrioles. ***If needed, use your textbook and notes to help you.***