Sept. 19th Lab Report Additional Materials

Cell Lab—Estimating Sizes Under the Microscope

Hi Everyone,
There were a lot of questions about estimating size under the microscope and I know there was a lot of confusion about calculating the size of the field of vision. Please take a look at the images compared to each other.

Remember that we are just doing an estimate---this doesn’t have to be 100 % accurate but I hope this will help.

1. Print out the attached power point slides so that you can compare the cells.
2. Use a ruler to break up each field along the diameter (the line through the middle of the circle).
3. Start with the amoeba, which is the largest. Under high power (400x) the amoeba fills almost the entire field of vision which most of you calculated to be 450 microns.
4. Look at the amoeba under 100x which has a field of vision of 2,000 microns. Does the amoeba fill about 1/5th of the line along the diameter? Which is the easier magnification to do the estimate under
5. Please remember that bacteria, amoebas and frog blood cells are ALL single cells.

Please email or call if you are still having trouble!
Thanks for all of your hard work,
Teresa