M5: Module 5 Exam - Requires Respondus LockDown Browser + Webcam

Ques 3 / 3 pts tion 1 Your Answer: The concept of treating all samples, whether known or unknown, as potentially hazardous (or pathogenic) materials is known as __________. Universal Precaution Universal precautions Ques 3 / 3 pts tion 2 List at least 3 observations a researcher would be sure to note while assessing an unknown microbial sample. 5/1/22, 6:14 PM M5: Module 5 Exam - Requires Respondus LockDown Browser + Webcam: Essential Microbiology with Lab-2021-Bowman Your Answer: Three observations are; The Gram status; either positive or negative The shape, size and observe any motility The presence of any chemical reactions A lab researcher would be certain to note: 1. Size and shape 2. Any observable motility 3. Gram status (positive or negative) 4. The presence of any chemical reactions 5. Changes in color localized to the organism or the surrounding media 6. Capture (or draw) images of any of the characteristics described above Ques 10 / 10 pts tion 3 Your Answer: While observing an unknown sample of limited amounts, a researcher must determine the following observations: (1) the presence of any motility and (2) its Gram status using the same sample—the liquid sample cannot be divided. Which would you determine first and why? I would first determine the presence of any motility before its Gram status; because checking for presence of motility requires that you use a wet mount. Gram status requires that you heat fix the sample and by doing that the sample can be killed; also you cannot determine the presence of any motility in Gram status that has been heat fixed. Since the liquid sample cannot be divided, its most adviseable to check for the presence of any motility first then you ca heat fix the liquid for for Gram status. 5/1/22, 6:14 PM M5: Module 5 Exam - Requires Respondus LockDown Browser + Webcam: Essential Microbiology with Lab-2021-Bowman You must determine motility before determining the Gram status. Motility requires a wet mount, while Gram staining requires heat fixing the sample. If one were to begin with the Gram stain the heat fixation process would kill the organism, making any observations regarding motility impossible. The correct approach would be to place the liquid culture on a glass slide and determine its motility status. Next, the same liquid culture can be heat fixed and Gram stained. Ques 3 / 3 pts tion 4 Your Answer: A facultative anaerobe is a microorganism capable of growth under what conditions? Facultative anaerobe is a microorganism capable of growth under aerobic and anaerobic conditions. A facultative anaerobe is capable of growth under aerobic (with oxygen) and anaerobic (without oxygen) conditions. Ques 10 / 10 pts tion 5 Your Answer: As Streptococcus is catalase negative would it thrive or die in the presence of peroxides? Why? 5/1/22, 6:14 PM M5: Module 5 Exam - Requires Respondus LockDown Browser + Webcam: Essential Microbiology with Lab-2021-Bowman Streptococcus would die in the presence of peroxides because it is not capable of breaking down peroxides the reason why it is catalase negative. if it stays long in the peroxide ith damages the cellular intergrity of the streptococcus and hence cell death occurs. Streptococcus would not survive in the presence of peroxides —it is unable to breakdown peroxides (catalase negative). Left unchecked, peroxides would damage the cellular integrity of Strep causing lysis/cell death. Ques 2 / 2 pts tion 6 Streptococcus is most often streaked onto: Spirit Blue agar Chocolate agar EMB agar Blood agar Correct! Strep is often cultured on Blood agar plates to determine its hemolytic properties, which aids in the classification (and differentiation) process. Ques 2 / 2 pts tion 7 True or False. The Lancefield groups are used to subdivide antigenic groups of gamma-hemolytic Streptococcus. 5/1/22, 6:14 PM M5: Module 5 Exam - Requires Respondus LockDown Browser + Webcam: Essential Microbiology with Lab-2021-Bowman True False Correct! The Lancefield groupings are used to subdivide beta-hemolytic Strep. Ques 2 / 2 pts tion 8 The distinctions for Lancefield subgroupings lie in its: (select all that apply) Carbohydrate composition of antigens Correct! Carbohydrate composition of antigens present in the cell wall determines the Lancefield groupings (A, B, C, etc). Note, ALL strep under Lancefield groupings are (by definition) catalase negative and beta-hemolytic. Thus, answers A and C cannot be used to subdivide streptococcal species. Hemolytic activity All of the above Catalase activity Ques 2 / 2 pts tion 9 Left untreated, strep throat can progress to ______ , which displays _____ hemolytic activity. Strep. Pharyngitis; alpha 5/1/22, 6:14 PM M5: Module 5 Exam - Requires Respondus LockDown Browser + Webcam: Essential Microbiology with Lab-2021-Bowman Strep. Pharyngitis; beta Rheumatic fever; beta Correct! Strep throat (also known as strep. Pharyngitis) can lead to Rheumatic fever if left untreated. Strep. Pharyngitis displays beta-hemolytic activity. Strep. Septicemia; gamma Ques 2 / 2 pts tion 10 True or False. Under most circumstances, staphylococcus can be found in ~80% of human population where it remains non-symptomatic. True False Correct! Staphylococcus in only found (non-symptomatic) in ~30% of the human population.