Virtual Microscope Lab - Cheek Cells KEY

Original Document: Virtual Microscope Lab - Cheek Cells

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 obtained cheek cells 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 or write answers on notebook paper.

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.

Drawings vary, check to make sure the relative sizes are correct. High Power should show only a couple of cells that take up most of the viewing field. The micoscope is designed to view the slide at different spots, so not all drawings will look like this one. Images were snipped from the virtual microscope's flash animation.

Scanning (4)

cells at 4x

Low (10)

cells at 10x

High (40)

cells at 40x

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? they are all irregular to round in shape, with a dark spot in the center

How do the cells vary from one picture to the next (how are they different)? colors vary depending on the kind of stain, size varies depending on magnification

4. Why are the google images of cells different colors? What is the natural color of a cheek cell? cells are stained for easier viewing, normally they are clear

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

eukaryote - type of cell that has a nucleus

nucleus - control center of the cell, contains the cell's genetic information

cell membrane - the outer boundary of a cell

cytoplasm - the fluid within a cell where organelles float

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?) lysosomes