Ap Biology Final Lab Report

The preparation for this lab should be done a week prior to examining each layer. The preparation consists of compiling the pond. To do so, obtain a small, disposable bowl with a cover. Using a thumbtack, poke holes into the lid of the container. Then, using black paper, wrap it 2/3 of the way around the bowl and proceed to the securing the black paper with aluminum foil. Once that’s completed, fill the bowl 1/4 way with soil and hay. Next, the bowl is filled with water 3/4 way. Cover the bowl, and allow it to sit by the window for about a week before observing. To begin observation, obtain and label three pipets: “surface,” “middle,” and “bottom.” The usage of three different pipets for each layer is to avoid cross continuation. Obtain three different slides and coverslips. Using the surface pipet, take a small sample of pond water form the surface and place one drop on the slide. Place a coverslip on it and then examine under the microscope. Using the objectives, switch to higher magnifications to observe details. Record the observations and using the dichotomous key, identify each type of organism. Repeat the same steps for the middle and …show more content…
Based on the layer assigned by the professor, use a clean pipet to obtain a small sample of water from the assigned layer and place five drops into a micro centrifuge tube. Along with the pond sample, place one drop of Protoslo Quieting Solution and invert the tube to mix the contents. Once inverted, pipet one drop of the solution onto a new slide and cover with a grid coverslip. Randomly select a square and count the number of organisms seen and record. Select another square and record the number of organisms. Repeat the same procedure for the remaining two layers and add the results of the grid count. Estimate the total number of each organism in the sample by multiplying the results for each organism by