Project One: Pond Organisms
The three objectives of this project are to have students prepare a wet mount slide, use a microscope to locate organisms in the pond water and identify the organisms in different regions of the pond water.
The first material is pond water, which you can obtain from your local pond or you can purchase through a science supply company. The other materials are microscopes, slides, cover slips, droppers and paper towels (to clean up afterward). Students should bring pens/pencils and notebooks to make sketches of what they see.
The procedure is as follows:
- Students use droppers to take top layer pond water samples from the pond water container.
- Students put one drop of pond water on the center of the slide.
- Students carefully lower the cover slip on top of the pond water sample.
- They put the slide on the stage of the microscope.
- They focus and observe pond organisms under low power.
- Once they locate organisms, they switch to high power.
- Students make sketches of the different organisms they see.
- Sketches should be labeled “Top Layer.”
- After students are finished, they should rinse off and dry the slides or teachers should administer brand new slides.
- Students should repeat this procedure two more times, taking from the “Middle Layer” and then “Bottom Layer” of the pond water.
Teachers can ask these discussion questions:
- Are there any similarities or differences in the types of organisms they see from the three layers?
- Why are there similarities and differences?
- What could be a reason for these similarities and differences?
- What type of organisms would you expect to be found in the top layer and bottom layer?
Students should clean up work stations. All lab material should be cleaned and dried and returned for storage. Teachers can collect students’ sketches.
To grade this project, teachers can evaluate the effort put into the sketches, answers to discussion questions and how well the students participated in the project.
Project Two: Food Webs
To branch off of the aforementioned project, students can compare their own sketches to this organisms in pond water chart. Students will use this chart to help identify and name the different types of organisms.
Teachers can assign an Internet project in which students can find information about the organisms and see where they fit in a food chain or food web. Students can identify these organisms as producers or consumers. Students should print out above chart and cut out the pictures. They can use these pictures to help build a food web.
The two objectives of this second project are to identify the role of the organisms in a pond water community and to correctly place organisms in trophic (feeding) levels on a food web.
To grade this project, teachers can evaluate if the students are correct in their identification of the organisms, if the organisms are correctly placed in the food web and the effort of neatness put into the project.
Thank you to high school biology teacher, James Murphy
Photo by Salvatore Vuono / FreeDigitalPhotos.net — freedigitalphotos.net/images/view_photog.php?photogid=659