Lab 1 Assignment Template (1)

Fall 2023 Lab 1 - The Microbiology of River Water BIOL 1103 1 Lab 1 Experimental Assignment Full Name: Reese Cournoyer Student #: 101297328 Lab section: A07 Although the experimental work will be completed in pairs, all work submitted must be completed individually. It is important that you do not copy from the lab manual or from each other. DO NOT plagiarize! Remember to properly cite and reference any external sources used (refer to Appendix 1 for guidelines). Unless otherwise specified in the question, all answers should be written using complete sentences, paragraph style. Part I: Observing the Microbiome of Raw River Water 1. Using your unaided eye, briefly describe the raw river water as if you were making observations for a lab report (3 marks) . Observations of the Rideau Canal ’ s raw river water: 1. Colour/Transparency: In the container, the water is transparent as you can see all the particles inside, with a brownish tone. 2. Matter: On the surface, there is a variety of small green and brown debris, including twigs, different plants and leaves as well as moss. Floating inside the water, you can find smaller twigs, more sediments and brown particles that tend to sink to the bottom rather than float. 3. In the small drop on the glass slide, the water is clear and transparent, though a tiny organism that resembles a spec can be found moving around in the water drop. 4. Odor: The river water does not smell strong, it has the smallest hint of earth, due to the debris or vegetation. 2. Using complete sentences, write a detailed description of the general characteristics of the organism that you will draw (in Question 3) from the raw river water. Include details regarding the shape, texture, and colour of the specimen. Describe the general thickness of the cell wall and/or the plasma membrane and whether any organelles were visible (3 marks) . The organism that was found is believed to be a type of single celled green algae called Chlamydomonas. This is a unicellular oval shaped organism, that has a bright green colour which is visible in the compound light microscope. The reason it is green is because they contain chloroplasts in order to complete photosynthesis. Also, this organism can move actively with its two flagella probably to get the nutrients that it needs. These flagella are slightly longer than the organism ’ s length. Through the 100X lens on the microscope, the organelles that can be seen are the chloroplasts and flagella. The chloroplasts inside the cell are seen as green, circular or spherical structures and the flagella are two hair-like structures at the peak of the oval

Fall 2023 Lab 1 - The Microbiology of River Water BIOL 1103 2 shaped cell. During this experiment, no other organelles such as the nucleus, pyrenoid, eyespot or mitochondrion were visible. The plasma membrane of this Chlamydomonas is relatively thin as it is not quite visible, however the cell wall is larger and can be seen as a clear substance surrounding the cell. Finally, the texture of the specimen can be described as having a smooth surface, because it is a simple cell that does not have any rough surfaces. 3. Create a detailed diagram of the specimen that you described in Question 2 (3 marks) . (You may insert an image of your lab notebook diagram, provided it is in the correct format, see Appendix 2). Table 1. General Characteristics of the specimen. Organism ’ s Colour Organism ’ s Organelles Organism ’ s Texture Organism ’ s Shape Organism ’ s Thickness Bright green with a clear substance (cell wall) surrounding the cell. You can find chloroplasts inside the cell which are seen as green, circular or spherical structures and the flagella which are two hair-like filaments at the peak of the oval shaped cell. Smooth or slimy looking surface, with no rough or hairy spots. Unicellular, oval shaped with two flagella at the top of the cell. Both plasma membrane and cell wall are relatively thin, cell wall being larger than the plasma membrane which is barely visible. 4. In the space below, calculate the actual length of your specimen from Question 3 and its magnification based off of your figure. Show all calculations and work (4 marks) . Actual Specimen Length Figure Magnification

Fall 2023 Lab 1 - The Microbiology of River Water BIOL 1103 4 microorganisms, sediment or algae to get through this filter. This is why I was not expecting there to be nothing visible in the filtered water. Part III: Treating and Observing the Microbiome of the Filtered River Water 8. Before you run your experiment in Part III, create a hypothesis. What are your predictions for the experiment (2 marks) ? During this experiment, I believe that the treated water will have the less colonies, or none, because it is completely sterilized to kill all bacteria from the river water. The filtered water might have some since it is possible for bacteria to get through the water filtering process. Whereas the raw river water will have the most since it is left untouched with known bacteria and life living inside. Part IV: Inoculating Plate across Treatments and Comparing Microbial Growth 9. What is the purpose of flaming the inoculation loop (1 mark) ? The purpose of passing this inoculation loop is simply to sterilize it before and after each use, to guarantee the accuracy of the experiment to avoid spreading bacteria. 10. Compare the plating results and elaborate on what trends (if present) you saw. Which of the techniques, if any, were effective in sterilizing the water (2 marks) ? With the plating results from a different group, it was clear to see the differences between the types of waters. The treated water had no colony growths, which is why treated water is the most effective, whereas the river water had the most colonies, and the filtered water sat in between the two. Create a properly formatted table below including the colony count data from your petri dishes (2 marks) . Table 2. Estimated colony growth of different water types. Raw river water colonies Treated water colonies Filtered water colonies 200+ 0 50 - 75 11. Based on colony growth on the agar plate, was your hypothesis supported in Part III. Refer to your data from Question 11 (3 marks) .

Fall 2023 Lab 1 - The Microbiology of River Water BIOL 1103 5 My hypothesis was correct in the beginning of part 3, because I assumed that raw river water would have the most colony growth (over 200 colonies), and the treated water would have none (0 colonies), and finally the filtered water had a few colonies growing from bactera that was not filtered out properly (50 – 75 colonies). This assignment is due 1 week after completing your Lab 1 session, but must be submitted to Brightspace on the hour prior to your next session (i.e., 8 AM or 1 PM, depending on your section). IMPORTANT : Tutorial 1 will be held in TB 202 starting the week of Oct. 2 (Group 1) and Oct. 9 (Group 2). Refer to schedule in Brightspace, or ask the lab coordinators if you have any questions.