Reference no: EM133999553
The scientific method is a method by which scientists methodically and objectively test hypotheses using scientific experimentation. The scientific method involves the following steps: make an observation, ask a question, develop a hypothesis, make a prediction, design and carry out an experiment testing the hypothesis, analysis of the results, reach a conclusion and share results (publish) and/or restart the process by tweaking the hypothesis or experimental design. Your entire textbook is based on experiments that were conducted using the scientific method. I want you to think about the scientific method as you go through the VLE. If you would like a quick refresher on the scientific method.
Questions:
1. At the very start of the simulation the video talks about what you are going to do. Describe, what you are testing for in this virtual lab simulation and what types of disposable equipment are you going to use (mention three types of disposable lab equipment, what are they and what are they for).
2. What types of milk are you going to compare in this experiment? What are you comparing between the milk samples? Define what is pasteurized milk.
3. Before you continue to click, I want you to create a hypothesis regarding what you would expect to see between the two milk samples (raw and pasteurized). A hypothesis is "an educated guess" or "possible explanation". A hypothesis needs to be specific and testable. I want you to create a good hypothesis. Here is an example of a good hypothesis "Dandelions growing in nitrogen-rich soils for two weeks develop larger leaves than those in nitrogen-poor soils because nitrogenstimulates vegetative growth". This is a good hypothesis as it includes an independent variable (nitrogen poor versus nitrogen rich soils), a dependent variable (thing you will measure, in this case larger leaf size) and a mechanism (because nitrogen stimulates vegetative growth). Write a hypothesis that has those three elements (independent- think the two different kinds of milk, dependent could be number of bacteria, mechanism- what does pasteurization do and how that would impact bacterial colonies/growth). Put it together.
4. Describe the steps for setting up the experiment (how samples will labeled, types of equipment for moving bacteria/samples etc). You should be describing the set up/design of the experiment including the labeling, inoculation, incubation, etc. Explain why microbiologists use an incubator and why it takes so long to grow bacteria.
5. Which sample had more bacteria colonies, the raw milk or the pasteurized milk? Did this result fit with your hypothesis (did your results support or does it cause you to reject the hypothesis that you created?).
6. What is Escherichia coli and why is it a concern in food plants? In this video they are testing different areas of the facility to test where the contamination is occurring. Does this sound applicable in the real world?
7. Describe some of the different swabbing techniques (dry versus wet). How long should samples be stored before use in an experiment? Describe the counting versus colony estimate approach that were used to analyze the different amounts of bacteria from the samples. Describe the results they found.
8. Describe the results of swabbing the different parts of the plant for E. coli (counting versus estimate, which sample had more bacteria). Did the pasteurization process work? How do you know? How was the disposable equipment disposed?