Lab+1+Organelles+in+Animal+and+Plant+Cells

Pre-Lab Questions:
1. List the three parts of the Cell Theory in your own words. 2. Write a brief description of each of the following:
 * 1) Organelle
 * 2) Cell membrane
 * 3) Cell wall
 * 4) Nucleus
 * 5) Eukaryote

3. Describe the correct way to make your own slide for viewing your cheek cells. 4. List three things you will NOT do when using the microscope to view your cells. 5. Why is it necessary to use a stain in this lab exercise? 6. Which stain do you use for your cheek and skin cells? Plant cells?

**Creating your own slides - Cheek Cells:** Read the procedure carefully. Procedure: 1. Before you begin, make sure your slide and coverslips are clean. You don’t want lint or fingerprints on your slide. If the slide is dirty, rinse it off and dry it well with a paper towel. 2. Put a drop of methylene blue on a clean slide. __**Caution: Methylene blue will stain clothes and skin.**__ 3. Gently scrape the inside of your cheek with the flat side of a toothpick. Scrape lightly. 4. Stir the end of the toothpick into the stain and __throw the toothpick away__. 5. Place the coverslip at a 45-degree angle on the edge of the water/saliva mix. Allow the liquid to spread down the edge of the coverslip. Once it has spread, carefully lower the coverslip over the liquid. — If you have a lot of air bubbles regardless of size, rinse of your slide and start over. It’s important that you make a good slide. 6. Use the SCANNING objective to focus. You probably will not see the cells at this power but you can eliminate blurriness by focusing now. 7. Switch to low power. Cells should be visible, but they will be small and look like irregular shaped objects similar to the cells below.
 * 1) Once you think you have located a cell, switch to high power and refocus. (Remember, DO NOT use the coarse adjustment knob at this point!)
 * 2) __**Written work**____**: Draw a picture of your cheek cell. Label the cell membrane, cytoplasm, and nucleus.**__
 * 3) DO NOT RINSE OFF YOUR SLIDE UNTIL YOUR INSTRUCTOR HAS SEEN IT – YOU ARE RECEIVING CREDIT FOR YOUR LAB PRODUCT, TOO!

1. Peel a translucent piece of tissue from the onion. The smaller the piece the better. (Translucent means that you can see light through the specimen, but it is not transparent.) //2.// Place the piece of onion on a glass slide and add a drop or two of the //iodine solution.// 3. Cover the slide with a cover slip using the same technique that you used for your cheek cells. 4. **__Written work: Observe the onion cell under both low and high power. Draw a diagram of the onion cell. Label the cell wall, cell membrane, cytoplasm, and nucleus.__** 5. DO NOT RINSE OFF YOUR SLIDE UNTIL YOUR INSTRUCTOR HAS SEEN IT.
 * Creating your own slides - Plant Cells:**

=Cleaning Up= 1. Rinse off your slides and coverslips. Dry them with a paper towel and return them too the center of the lab table where they were found.
 * 1) Make sure the stain and medicine droppers are at the center of the lab table next to the slides and coverslips.
 * 2) Turn off the microscope, unplug it, and put the cover on it