Paramecium

Virtual Lab: Population Biology How to get there: Go to the following website: http://glencoe.mcgraw-hill.com/sites/dl/free/0078757134/383928/BL_04.html If you do not want to type all that in you can go to type "biology mader aris" into google. Once you are there and see the textbook cover (bird and chicks) go to the tab at the top that says "resources". Scroll down to "Chap 46", open that page and click on the link to "Virtual Lab - Population Biology". Purpose: In this investigation you will conduct an experiment and grow two species of the protozoan Paramecium, alone and together. You will then compare growth curves of the populations of each species. Objectives: (1) Demonstrate how competition for natural resources in the environment can affect population growth. (2) Explain how availability of resources, such as food, can be limiting for populations. Instructions: This lab has instructions on the left hand side and also contains pages to enter data and questions. I typed out the online instructions below in more detail for clarity. Also, instead of typing directly into the online data table and journal, I request that you write your answers in the data table on the next page and answer the journal questions on the following pages of this packet. 1. Read over the objectives of the lab on the left hand side of the webpage. 2. Click on "More Information" to read about Paramecium and about population growth and competition. 3. Answer Journal Questions #1. 4. Begin the experiment by filling the test tubes with samples from the stock cultures in the flasks. Click the bulb at the top of the pipette to fill the pipette with culture. Then click and drag the pipette to a test tube. Fill the three test tubes with Paramecium aurelia, Paramecium caudatum, and /or a combination of both. Note: There is rice in the test tubes. The rice is food for bacteria, which in turn will be food for the Paramecium. The two species of Paramecium do not prey upon each other. 5. Click the Microscope on the back shelf to go to the lab bench. Then you will make wet mounts of the samples. 6. Click the Clean Microscope slides box to set up clean microscope slides. 7. Click the test tubes to prepare wet-mount slides of the samples. 8. Click and drag a wet mount to the stage of the microscope. Count or estimate the number of cells of each type of Paramecium. Click the Grid On button for help with counting. 9. Record you data in the Data Table. NOTE: The well in the microscope slide holds 0.5 mL. You need to multiply by 2 the number of cells you counted or estimated in order to obtain the concentration per mL. 10. Click the Clear Slides button. Click the Calendar to advance it by two days. Then get a new set of clean slides, place samples on them, and count or estimate the number of Paramecium you see. Record your data in the Data Table. 11. Continue the steps above until the Data Table is complete. 12. Graph your data in a line graph. You may do this in Excel or use graph paper, a ruler, and different color pencils.