BIO250L LAB 1

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Grand Canyon University *

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250L

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Biology

Date

Jan 9, 2024

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“ Lab 1 Introduction to Science BIO250L ” Student Name: MA ERICKA RENEE SAUVE Access Code (located on the lid of your lab kit): UAWQHC Lab Report Format Expectations Utilize college level grammar and professional formatting when completing this worksheet. Submissions without proper formatting, all required photos or sufficient responses will be rejected. Pre-lab Questions 1. In this course, you will utilize several types of growth media to observe the nature of microorganisms. How can you protect yourself from any microorganisms that you may work with in the upcoming labs? We can protect ourselves by using personal protective equipment and following the required SOPs. 2. What constitutes personal protective equipment? When should personal protective equipment be worn? Personal protective equipment includes safety goggles, gloves, lab coats, and shoe covers. It is used when conducting experiments. 3. What is meant by “BioSafety Levels”? Why do researchers utilize these when working with microorganisms? What level of biological containment (which BSL) will be necessary to complete the experiments in this course? Biosafety Levels (BSL) are a set of protection and safety measures implemented in laboratories to handle pathogens and biological materials safely, based on their potential risk to humans and the environment. These levels range from L-1 to L-4, with each level corresponding to an increased level of containment and safety measures. For this experiment, L-2 will be sufficient. 4. What document should you refer to if you have questions regarding the safety or disposal of a chemical? Where can this document be located? I always refer to the Material Safety Data Sheet (MSDS) for questions regarding chemical safety and disposal. I can find it at www.esciencelabs.com.

“ Lab 1 Introduction to Science BIO250L ” “ EXERCISE 1: DATA INTERPRETATION 1. What is the overall goal of this exercise? What learning outcomes is it trying to convey to you as a science student? The ultimate objective is to observe and derive any hypotheses from the conducted experiment. 2. What patterns do you observe based on the information in Table 4? Table 4 suggests that microorganisms tend to decrease at the extremes of pH levels, but they increase when the pH is neutralized to 7. 3. Describe the hypothesis the researcher may have used in the experiment that provided the data in Table 4. Format your response as an IF/THEN statement that describes what you will do, and the outcome you expect to see. When the pH of the environment becomes neutral (pH 7), the population of microorganisms tends to increase. 4. Describe a possible experimental setup that could have provided the data in Table 4. Microbial cultures were established, and their populations were recorded at varying pH levels. 5. For the experiment you described above, what would be the independent and dependent variables? pH is the independent variable. 6. What experimental control variables would need to be in place to ensure the proper execution of the experiment you described? Neutral pH is the experimental control. 7. Why is it important to have those controls in place? How would a lack of those controls affect any results or conclusions you may make about the observed data? With the lack of control, we can't compare results and hence we can't make a hypothesis. 8. What type of graph would be appropriate for this data set? Why? Using a line graph would be appropriate to depict the increase and decrease of microbial population at different pH levels.

“ Lab 1 Introduction to Science BIO250L ” 9. Graph the data from Table 4. Include your name and access code handwritten on your graph. 10. What conclusions can you draw from the data from this experiment? Microbes tend to die at both extreme pH levels; their ideal pH for growth is 7 as shown on the graph. EXERCISE 2: TESTABLE OBSERVATIONS 1. In this exercise, you will be provided several statements and then be asked to identify and discuss possible experimental factors that could be used to test them. For each of these statements, you will be asked to discuss a pertinent hypothesis and null hypothesis. What is a null hypothesis? Why is it crucial to the scientific method? A null hypothesis is a statement that states there is no effect or difference between two corresponding groups of an experiment. It is crucial as it provides a standard for statistical testing. 2. Fresh-baked bread develops mold more quickly than bread bought from the store.

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“ Lab 1 Introduction to Science BIO250L ” a. Observation is Quantitative b. Hypothesis: Freshly baked bread will develop molds quickly because they don't have added preservatives. c. Null hypothesis: Both freshly baked bread and store-bought bread will develop mold at the same rate. d. Experimental approach: A slice from both pieces of bread will be exposed to air to observe which develops mold quickly. e. Independent variable: Time taken. f. Dependent variable: Preservatives added. g. Experimental Controls: Cheese. h. Data collection method: Through photography i. Data presentation: Photos taken before and after mold development, with dates on each. j. Data analysis: Photos taken at different times for both breads will be analyzed 3. Sally comes to work sick; two days later, three of her coworkers are also sick. a. Observation is . Quantitative b. Hypothesis: If a healthy person comes in contact with a sick person, there is a higher chance of the healthy person becoming ill.

“ Lab 1 Introduction to Science BIO250L ” c. Null hypothesis: Exposure to both healthy and sick individuals does not affect the health of an individual. d. Experimental approach: We need to split 6 healthy people into two groups, one spending 6 hours and the other spending 3 hours with the one person who has the flu. e. Independent variable: What is the recommended length of time for a healthy individual to be close to someone who is sick without risking exposure? f. Dependent variable: Number of individuals getting sick. g. Experimental controls: One individual with no exposure to a sick person. h. Data collection method: Will see signs and symptoms of exposed persons. i. Data presentation: Individuals may develop signs and symptoms based on the duration of their exposure. j. Data analysis: Each individual's health and severity of symptoms will be analyzed and noted for each group member. 4. You accidentally left a carton of milk on the counter all night, and you notice that the milk tastes worse than it usually does when it is stored in the refrigerator. a. Observation is . Qualitative b. Hypothesis: Milk out of the freezer will lose its freshness and taste. c. Null hypothesis: Milk will not spoil whether it is kept in the refrigerator or outside of it.

“ Lab 1 Introduction to Science BIO250L ” d. Experimental approach: Place one cup of milk on the counter, one at the door of the fridge, one at the top shelf of the fridge, and one at the bottom compartment of the fridge. Observe after 24 hours. e. Independent variable: Temperature f. Dependent variable: Milk quality g. Experimental controls: Milk has been delivered to the door. h. Data collection method: The taste of every milk sample will be recorded 24 hours after. i. Data presentation: Varying tastes of each milk will be presented on a scale of 1 to 4, with 1 being the most refreshing and 4 having a poor taste. j. Data analysis: Three types of milk will have similar tastes, while the milk stored at the top shelf of the fridge will be the freshest. EXERCISE 3: ACCURACY AND PRECISION 1. In the following questions, you will be asked to assess whether the observed data is precise, whether it is accurate, whether it is both, or whether it is neither. Before answering those questions, describe below the difference between accuracy and precision. Accuracy means how close a measurement is to the true value, while precision determines the consistency of repeated measurements. Accuracy is about correctness, and precision is about correctness after repeatability. 2. Four new students are learning how to count bacteria colonies. They all count the same plate, and the first student counts 98 colonies, the second counts 115 colonies, the third counts 103 colonies, and the fourth counts 93 colonies. The professor tells them there are actually 107 colonies on the plate. Both are precise and accurate

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“ Lab 1 Introduction to Science BIO250L ” 3. You want to make sure your incubator is operating at the correct temperature of 37˚C, so you place a thermometer inside the incubator and check it every hour for five hours. You record readings of 36.9˚C, 36.9˚C, 37.1˚C, 37.0˚C, and 37.1˚C. Precise and accurate 4. You aren’t sure whether or not your pH meter needs to be calibrated, so you put it in a solution that you know has a pH of 7. Take four separate readings, which are reported as 5.5, 8.6, 7.2, and 9.4. Neither 5. Your lab is working on sequencing a new plasmid. Before starting, you all decide to guess how many base pairs you think the new plasmid has. The lab members’ guesses are 4,005; 4,006; 4,007; and 4,010. It turns out the plasmid has 7,968 base pairs. Precise 6. You try to measure out exactly 5.0 mL of water by eye into five different test tubes. When you go back and check, you find the amount of water in each tube is 4.8 mL, 5.3 mL, 5.2 mL, 4.8 mL, and 4.7 mL. Both EXPERIMENT 1: THE IMPORTANCE OF HAND HYGIENE Introduction Questions 1. In this experiment, you will grow microorganisms on agar and observe their growth over a 5 day period. What is the objective of this experiment? How does it relate to the concepts covered in this lab? This experiment aims to observe the growth patterns, characteristics, and behavior of microorganisms over a 5-day period on agar. It helps determine the pattern of growth, culture techniques, and conditions required for growth. 2. What steps will you be taking in this experiment? To conduct the experiment, I will sterilize materials, pour agar in Petri dishes, streak

“ Lab 1 Introduction to Science BIO250L ” microorganism sample, incubate at 37°C, observe daily changes, dispose of culture safely, and compile results. Prioritize safety and adhere to lab protocols . 3. Develop a hypothesis for this experiment as an IF/THEN statement . If microorganisms are provided with the optimum nutrients and environmental conditions on an agar plate, then they will thrive and produce visible colonies over a 5-days. Data and Observations In the table below, report your observed growth. Then provide a photo of your growth plates. Your data should have a quantitative aspect to it, such as a count of the number of colonies that grew. Your data must also correspond to the photo you include for credit. Table 1: Colony Growth Plate Condition Growth Day 1 Growth Day 2 Growth Day 3 Growth Day 4 Growth Day 5 1 Hand without Washing 4 12 26 33 40 2 Hand with Washing 0 1 14 20 29 3 Yeast 0 1 2 2 2 4 Deionized Water 0 0 0 0 0 Provide a clear, high resolution photo of your plates after incubation with the lids removed. For credit on this lab, your photo must show the growth that is reported in your tabulated data and must also include your handwritten name in the background.

“ Lab 1 Introduction to Science BIO250L ” Results and Discussion 1. What is the outcome of your experiment? Was your hypothesis proven or disproven? How do you know? The hypothesis was confirmed. I determined this through daily observations of colonies on agar plates and by providing optimal conditions. 2. What purpose did plating the yeast serve in this experiment? What purpose did the water serve? In the experiment, plating yeast served as the control group. We compared it with our experiment to gain a better understanding of how microbes grow in ideal conditions. Water purification served as a negative control. 3. Based on your hypothesis and the results of your experiment, can you make any conclusions about the effects of handwashing on bacterial populations? Handwashing effectively decreases bacterial population on the skin 4. Did you have any growth on Plate #2 (Hand with Washing)? If so, what are some possible reasons for the presence of the bacteria? Inadequate handwashing, resistant bacteria, or hand recontamination after washing could have contributed to the growth.

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BIO250L LAB 1

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