Virtual Microscope Lab - Cheek Cells

Name ______Biology Make-up Lab

Introduction: If you missed the microscope lab we did in class, you will need to make it up by using a "virtual microscope" which can be accessed on the Internet. The virtual microscope is a little more complicated than the microscope we used in the lab, but it will not be difficult to use. In class, we worked with skin cells, but for this lab, you will be looking at cheek cells. Cheek cells are obtained by scraping the inside of the mouth with a toothpick and then rubbing the toothpick on a drop of water with blue stain. The blue helps you see the cells, which are normally a clear color. The virtual lab begins at the step where you place the slide on the microscope page. Print this page and draw your sketches and answer the questions for each part of the lab. Access the Virtual Microscope at http://www.udel.edu/biology/ketcham/microscope/ Click on the link that says "the virtual scope" 1. Familiarize yourself with the microscope, run the tutorial and examine the parts you will be working with. 2. View the slide labeled cheek smear. Sketch the image at Scanning, Low and High Power. LABEL on high power the CELL MEMBRANE, CYTOPLASM, and NUCLEUS. Scanning (4) Low (10) High (40)

3. Go to Google and type "cheek cells" into the search box. Click on "images" to see all the images Google has found on the web showing cheek cells (there should be hundreds).

What do all of these images have in common?

How do the cells vary from one picture to the next (how are they different)?

Name ______Biology Make-up Lab

4. Why are the Google images of cells different colors? What is the natural color of a cheek cell?

5. Use the Internet or your textbook to define or describe each of the following terms that relate to the cell.

Eukaryote

Nucleus

Cell membrane

Cytoplasm

6. Keeping in mind that the mouth is the first site of chemical digestion in a human. Your saliva starts the process of breaking down the food you eat. Keeping this in mind, what organelle do you think would be the most numerous inside the cells of your mouth? (Hint: what organelle is responsible for breaking things down and digesting?)

Plant Cell Lab

Purpose: Students will observe plant cells using a light microscope. Two cells will be observed, one from the skin of an onion, and the other from a common aquarium water plant (anacharis). Students will compare both types of cells. See also: Plant Cell Lab Makeup, which utilizes web resources to complete lab guide. Prelab Questions 1. What is the function of chloroplasts? 2. Name two structures found in plant cells but not animal cells. 3. Name three structures found in plant cells AND in animal cells. 4. What structure surrounds the cell membrane (in plants) and gives the cell support.

Procedure: Go to www.biologycorner.com/worksheets/plantcells.html which contains images of cells as they were viewed in the lab. You will use these images to complete this worksheet.

Part A - Onion Cells

Obtain a prepared slide of onion cells or prepare one yourself. View under the microscope and sketch the cells at each magnification. Label the cells as they Name ______Biology Make-up Lab appear under high power.

Part B - Elodea Cells View a prepared slide of elodea (anacharis), which is an aquarium plant. As the slide warms from the light of the microscope, you may see the chloroplasts moving, a process called cytoplasmic streaming.

Post Lab Questions 1. Describe the shape and the location of chloroplasts. 2. Why were no chloroplasts found in the onion cells? (Hint: think about where you find onions) 3. Which type of cell was smaller - the onion cells or the elodea cells? 4. Fill out the Venn Diagram below to show the differences and similarities between the onion cells and the elodea cells. Name ______Biology Make-up Lab