This is a variation of the pond water lab found abundantly in the web. This handout focuses on teaching the students the difference between unicellular and multicellular organisms found in fresh water ecosystem. Thanks to http://www.msnucleus.org/ for the Guide to Identification of Fresh Water Microorganisms. I appended the guide to this worksheet I created.
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Leeuwenhoek’s Animalcules (Pond Water Lab)
Learning Objective
Today, I will
1. differentiate between unicellular and multicellular organisms.
2. draw unicellular and multicellular organisms.
Materials
microscope, pond water culture, eyedropper, glass slide, glass cover, cotton, Guide to Identification of
Fresh Water Microorganisms
Procedure
1. Place some cotton fibers on the middle of the glass slide. The cotton fibers will trap or slow down
the “animalcules” and make finding them and focusing easier.
2. Using an eyedropper, put a very small drop of pond water on the glass slide.
3. Now look at the drop of pond water through the microscope at 40x magnification (eyepiece x
scanning objective).
4. Once you see a living thing, follow it closely and sketch it in the circles below.
5. Refer to the Guide to Identification of Fresh Water Microorganisms to identify the organism you
just drew. Write whether it is unicellular or multicellular.
6. Draw and identify at least 3 microorganisms. You can also use 100x magnification (eyepiece x low
power objective) to observe the organisms in more detail.
Illustrations
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Closure
What is the difference between a unicellular organism and a multicellular organism?
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