Ward's World Activity Guides

Exploring Microscopic Pond Life (student activity sheet) + ward ' s science 5100 West Henrietta Road • PO Box 92912 • Rochester, New York 14692-9012 • p: 800 962-2660 • wardsci.com Introduction: Before beginning focused explorations on various aspects of microscopic biology, it is useful and interesting to simply experience some of the abun- dance and diversity of life within the microscopic world. In this activity, you will consider the diversity of life found in pond water by searching for specific organisms and by identifying other organisms. You will refer back to this activ- ity and build upon it in subsequent activities. Procedure: 1. Prepare a slide of pond water. • Optional: Using a toothpick, put a small ring of methyl cellulose solution on a slide. (Note: Methyl cellulose solution is very viscous.) • Using a pipette or eyedropper, place one drop of pond water on the slide (in the ring). • Add a cover slip. • Label the slide with information about its source. 2. An image or movie of an organism will be projected in front of the class. Working with a partner, (a) try to locate one like it on your slide and (b) try to identify it using the available resources. a. Search your slide for the projected organism, using the microscope's eyepieces and mini-digital screen (and/or the computer screen). Note: Your slide may or may not have this organism. • Whenever you find an organism that you think might be the one projected, discuss it with your partner, compare it to the projected organism, and take an image or short movie to document your find. Alert your teacher to have your find confirmed. • Along the way, if you see any other organisms of interest, take images and/or movies of them for use later in this activity. Include information on the sample in and the magnification at which you found the organisms. b. Search the available resources for the identity of the projected organism. Consider such factors as structure (internal and external), size, color, motion, etc. • When you and your partner think you have identified the organism, record details about that organism and how you identified it. Alert your teacher to have your identification confirmed. 3. Repeat this for other organisms projected in front of the class and for other slides made from various water samples. Activity 2: Considering Microscopic Pond Life: 1. Prepare your own "Find and/or Identify the Organism I Am Showing You" images and/or movies. • Start with any organisms you photographed or took movies of earlier in this activity. Use the resources to try to identify them. • Search for, photograph and/or make a movie of, and try to identify other organisms that are common in your samples or that you find particularly interesting. • Select three organism images and/or movies to use for challenging other students. This can include organisms that you have not (yet) managed to identify, as long as you share this fact. 2. Present your challenge organisms to other students, and work on their challenge organisms in turn. Pond Name: Class: Date: Safety Remember to practice proper safety techniques in all science laboratory activities! !

• Cover