Reference no: EM133207884
Assignment: Effect of Temperature on Bacterial Growth- Virtual Scientific Method
How does bacterial growth vary under differing conditions?
Instructions
A. Open the virtual lab by clicking on the link below or copy and paste to an internet browser address bar.
B. The screen will display the virtual lab simulation with a short introduction and background information. As explained, you can decide one of the following factors to test. You will also want to make sure you decide which variables to standardize (keep constant throughout the experiment) to reduce any potential error, Finally, ensure you conduct your experiment more than once. At least 3 trials in each condition are recommended to validate your results.
1. Temperature (degrees Celsius)
a. Room temperature is 20C
b. Human body temp is 37C
c. A cold day is 10C
2. Antibacterial substance A amount in microliters (a small measure, 10-6 L)
3. Antibacterial substance B amount in microliters
4. Experimental duration (1 day, 2 day, 3 day)
C. Click "next" the blue button at the bottom of the page. The following screen continues the introduction and background information. Take note of the different forms of the bacteria you do want verses the bacteria you don't want or mold. Once you review the information, click the blue "Go to simulation" at the bottom of the page.
D. Before you begin your simulation, answer the questions below:
1. Which factor will you test in your experiment? (temperature, antibacterial substance A or B, or experiment duration) Remember a sound scientific experiment only changes one variable.
2. Which factors will you keep constant or the same during your experiment? These are the standardized variables.
3. What is the independent variable of the experiment?
4. What is the dependent variable of the experiment?
5. Which group represents your experimental group that you are changing?
6. Which group in your control group, representing normal conditions for comparison?
7. Clearly state your hypothesis below. Which condition will result in the most or the least bacterial growth? Remember the hypothesis is a sentence representing your best guess.
8. State your prediction below. The prediction rephrases the hypothesis as an if...then statement linking it to your experiment..
E. Once you set your experimental parameters, hit the blue "run simulation" button. Collect your data (count the number of bacterial colonies on the petri dish) and enter it into the table below. The first table is for your experimental group data. The second table is for the control group data
F. Click the reset button and run your experiment again. Remember a good experiment has multiple trials, at least three for the control group and three for the experimental group in our simulation..
Table 1.Bacterial growth under various conditions for experimental group.
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Growth of Bacteria
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Temperature
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Amt. of Antibacterial Substance A
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Amt. of Antibacterial Substance B
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Duration of Experiment
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Trial 1
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Trial 2
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Trial 3
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Average
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Table 2. Bacterial growth under various conditions for control group.
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Growth of Bacteria
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Temperature
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Amt. of Antibacterial Substance A
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Amt. of Antibacterial Substance B
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Duration of Experiment
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Trial 1
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Trial 2
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Trial 3
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Average
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G. Calculate the average bacterial growth for the control group and experimental group. Include that information in Table 1 and Table 2 above.
To calculate the average growth for each group use the equation below:
(Trial 1 + Trial 2 + Trial 3)/3 = average growth
H. Answer the following questions:
1. Explain why you need a control group for a sound experiment.
2. Which group had the greatest bacterial growth?
3. Which group had the least bacterial growth?
4. What do your results suggest about the effectsof your manipulation on bacterial growth?
5. Did you support or reject your hypothesis? How did you reach this conclusion based on the data collected?
I. Now that you have completed your experiment, you are going to share your findings with the class on Canvas in a discussion board post.
On the discussion board you will share:
1. Your initial hypothesis on how the bacterial growth would be impacted by the factor you investigated.
2. State the factor you manipulated. What factors did you keep the same as your standardized variables?
3. Explain the results of experiment: includeindependent and dependent variable, control and experimental groups and average number of colonies.
4. What can be concluded based on your results? Explain how the growth of bacteria is or is not affected by the variable you manipulated in the online simulation.
5. State whether your hypothesis was supported or not.
6. Respond to two classmates - did they manipulate the same factor? Get similar results?Have the same standardized variables?