Jinsun Moon AP Biology- 2nd February 8, 2011 Protists Lab Observing Various Types of Protists from Numerous Freshwater Samples Introduction Protists are various types of eukaryotic microorganisms. They are usually unicellular, or if they are multicellular, they have specialized tissues. Their name originates back to the 19th century, when biologist Georg A. Goldfuss used the word protozoa and Ernst Haeckel first used the term protista. Protists can be found in almost any environment that contains water. Their functions range from food to sea creatures such as plankton, to deadly human diseases such as malaria and sleeping sickness. The way they feed varies from creating their own food through photosynthesis to being parasitic and feeding off their host. Not only does their function and diet differ, some protists reproduce asexually through binary fission and some reproduce sexually.There are many different types of protists.They are often categorized into three different types of protists: animal-like, plant-like, and fungus-like. Some common examples of animal-like protists include Paramecium, Giardia Lamblia, and Plasmodium. A few examples of plant-like protists are Euglenoids, Chrysophytes, and various kinds of algae. Lastly, two types of fungus-like protists are water molds and slime molds. They all differ in the way they move and eat.Often, when trying to observe these protists under a microscope, we often use Protoslo which is a nontoxic, methyl cellulose solution that is used to slow down protists in order to be viewed in more detail. Just by placing a drop or two on the slide can change the way you view the protists completely. Also, when in the laboratory observing protists, you must be sure to calculate field of view (FOV) and cell size. This helps when comparing data from other freshwaters. Finding the field of view is very simple and can be done by counting how many millimeters across you see when looking through the microscope. Purpose The purpose of this lab is to identify the different types of protists living in different types of freshwater by using a microscope. Materials - Microscope - Coverslips - Slides - Pipets - Various types of Freshwater - Protoslo Method 1. Get sample of freshwater by using the pipet. 2. Place on clean slide. 3. Add tiny drop of Protoslo if necessary. 4. Gently apply a coverslip. 5. Place under a microscope. 6. Sketch what you see and identify the type of protist. 7. Record magnification and how many cells would go across. 8. Calculate field of view and cell size. Raw Data - See attached Processed Data Finding cell size: Field of View for 100x magnification: 1.5 mm Field of View for 400x magnification: .375 mm Cell size in mm Fielu of view in mmNumbei of cells in F0v Cell size in mm Fielu of view in mmNumbei of cells in F0v Converting to micrometers (m): Cell size in m Cell size in mm x Sample Equation: Airport Pond, 100x Cell size in mm mm Cell size in mm = .25 Cell size in m x Cell size in m = 250 Cell Size in m of Protists from Various Sources of Freshwater ProtistCell size in m Protist 1 (Meridion)250 Protist 2 (Clamydomonas)150 Protist 3 (Polycystis)93.75 Protist 4 (Perindium)100 Protist 5 (Pelomyxa)75 Protist 6 (Polycystis)166.67 Protist 7 (Thecamoeba)214.29 Protist 8 (Eunotia)25 Protist 9 (Ophiocytium)15 Protist 10(Actinophrys)125 Conclusion In this experiment, we were trying to identify different types of protists that existed in local freshwater bodies of water by observing tiny samples of different kinds of water on a slide. We recorded ten different kinds of protists from 5 different bodies of water. After drawing each sample out and comparing it to the scientific drawings, we found many different kinds of protists. The first protist we found was from the airport pond and I concluded that it was a meridian. After finding the field of view, counting the number of cells that would fit across the diameter, and converting to micrometers, the cell size turned out to be 250 m. Next, we found very interesting ones from the Gaberrone Pond. We found a Chlamydomonas with had a cell size of 150 m, a Polycystis with a cell size of 93.7 m, a Perindium with a cell size of 100 m, and a Actinophrys with a cell size of 125 m. Then, while looking in the sample labeled Tiger Point we observed a Pelomyxa with a cell size of 75 m. In Alys Meads backyard, we found another Polycystis with a cell size of 166.67 m and a Thecamoeba with a cell size of 214.29. Lastly from Preeyals Pond, we found a Eunotia with a cell size of 25 m feeding on some plant and aOphiocytium with a cell size of 15 m. From these observations, we can see Airport Pond had the biggest protist. Maybe if we were able to observe a few more protists, we would be able to see if all the protists from this pond were all big or if it was just the one we found. Alys Meads backyard had the next biggest protists. Samples from the Gaberrone Pond all had similar sizes ranging from around 100 to 150. Getting smaller, in the Tiger Point sample, the size was not small, but it wasnt very big either. Lastly, the smallest observations came from Preeyals Pond. They were very small, and we had to use 400 times magnification to be able to see them clearly enough to draw. The protists in her pond were very shy and bolted off before we were able to closely examine them. They moved quite fast even with the Protoslo. From this lab we can see the many different types of protists that have been discovered or have yet to be discovered. Evaluation Throughout this microscopy lab, there are numerous human errors that could have been made. First is sketching the protist. Although it needs to be in good detail to compare with the scientific drawings, maybe not drawing them clearly enough could have gotten us confused with other protists. Next, along with that error, we could have incorrectly identified the protist. Lastly, while looking under the microscope, when we had to count how many cells would fit across the field of view, we could have estimated wrong making the calculations for the cell size wrong.To prevent these errors in the future, one improvement that could be made in this lab is the making the drawings more detailed. If the sketches are drawn more clearly and with detail, identifying the protists could be easier. Also, having more scientific drawings to compare our drawings to, might help with identify the protist itself. Finally, taking more time to count how many cells would fit across the diameter might help make our lab more accurate. Maybe having more than one person estimate and comparing each others thoughts could contribute to the accuracy of the lab.