Download BIOD 171 Module 4 Exam(Latest,2024-2025)/BIOD171 Module 4 Exam(2 Vers):Portage Learning and more Exams Nursing in PDF only on Docsity!
M4: Module 4 Exam - Requires Respondus
LockDown Browser + Webcam
Attempt Time Score LATEST Attempt 1 28 minutes 98 out of 100
Score for this quiz: 98 out of 100
Submitted Aug 6 at 10:30am This attempt took 28 minutes.
Question 1
2 / 2 pts
True or False: Growth media is best suited for distinguishing between two similar species of bacteria. True Correct! False Growth media is designed to simply support (and not restrict) microbial growth.
Question 2
2 / 2 pts
A researcher is asked to determine which of two vials contains E coli and which contains salmonella. Knowing both are Gram-negative while only one of them is capable of fermenting lactose, which type of media would be best suited? Selective and Differential media Selective media Growth media
Correct! Differential media Differential media distinguishes between two, often related, microbes. Question 3
10 / 10 pts
What are the requirements of a fastidious microbe? Your Answer: A fastidious microbe is organism with complex growth requirements. If these growth requirements are not met, the organism will not grow. An enriched media must be to provide the correct nutrients to the organism to allow for growth. A fastidious microbe is an organism with complex growth requirements such that if absent it will not grow. Enriched medias thus contain these specific and essential nutrients required for the growth of a particular subset of microorganisms. Question 4
0 / 2 pts
True or False: LB agar is classified as a non-selective, non-differential media. Correct Answer True You Answered False Question 5
5 / 5 pts
What is agar used for in microbiology? Your Answer: Agar is used to create a solid, smooth surface on which microbes can grow. Agar is used to create a solid, smooth surface on which microbes can grow.
Correct! 3 Question 8
2 / 2 pts
Columbia CNA agar is most closely related to which media: Correct! Blood agar CNA agar is similar to BAP as it is also enriched with blood and allows for differentiation based on hemolytic patterns. EMB agar MacConkey Agar Trypticase Soy Agar Question 9
2 / 2 pts
True or False: Chocolate agar gets its brown color from cocoa to produce an enriched media. True Correct! False C A
Chocolate (cocoa) is never added to the media. The name is derived simply based on the color that actually comes from the presence of ‘cooked’ (lysed) red blood cells in the media. Question 10
5 / 5 pts
A researcher is studying a strain of E. coli currently growing on a MacConkey plate. However, the researcher can’t remember if E. coli is Gram-positive or Gram-negative. Would a Gram stain be necessary to confirm? Why or why not? Your Answer: A gram stain would not be necessary. Only gram-negative microbes will grow on MacConkey agar. E.coli is a gram-negative. No. A Gram stain would not be necessary, as only Gram-Negative microbes will grow on MacConkey agar. Thus, E. coli is a Gram-Negative microbe. Question 11
10 / 10 pts
In an attempt to detect the presence of the pathogenic strain of E. coli O157:H7, a researcher spread a culture onto a MacConkey agar with failed results. What type of agar should they (correctly) try next? Why? Your Answer: The next type of agar they should try is SMAC( sorbitoll mannitol agar). SMAC is used to detect E.coli 0257:H7. E.coli 0257:H7 is pathogenic and cannot ferment sorbitol. The non-pathogenic form of E.coli can ferment sorbitol and lactose. The microbe should be plated on SMAC (Sorbitol-MacConkey agar) as it is specifically formulated to detect O157:H7. Pathogenic E. coli (O157:H7) cannot ferment sorbitol while non-pathogenic E. coli can ferment both soribitol and lactose. Therefore, colonies that ferment (acidic conditions; non-pathogenic) can be differentiated from non-fermenters (neutral to basic conditions; pathogenic). Question 12
5 / 5 pts
In Eosin Methylene Blue (EMB) agar, what color indicates the presence of E. coli? Your Answer: metallic green Metallic Green
Correct! True To form a bacterial colony the initial cell must have multiplied many times over, often greater than a million, in order for the naked eye to resolve it. False Question 17
2 / 2 pts
True or False. The purpose of a quadrant streak is to produce individual colonies of a bacterial population. Correct! True The purpose of the quadrant streak is to generate individual colonies such that a single (pure) bacterial sample can be isolated. False Question 18
5 / 5 pts
To be considered a pure culture, the sample (1) can be traced back to a single cell and (2)__________? Your Answer: free from any external contaminates The culture must also be free from external contaminants. Simply put, a pure sample would never contain multiple bacterial species (ie) Strep and Staph. Question 19
5 / 5 pts
A dilution gradient is formed when carrying out what generalize plating strategy?
Your Answer: quadrant streak A quadrant streak. The resulting gradient should always contain within it the growth of individual colonies. Question 20
5 / 5 pts
In what phase of a dilution streak would you expect to find the lowest concentration of bacteria, P2 or P4? Your Answer: You would find the lowest concentration of bactiera in P2. P1>P2>P3>P P4 (Phase 4) would contain the lowest concentration of bacteria. The phases rank (from highest to lowest), P1 > P2 > P3 > P4. Question 21
2 / 2 pts
True or False. When performing a dilution streak a new (or sterilized) loop is not required for each phase as long as the bacterial culture is pure. True Correct! False A new or sterilized loop is absolutely required for each phase. Failure to do so would prevent the establishment of a dilution gradient, as the same bacterial concentration would be spread across both phase regions, regardless of whether or not the culture is pure. Question 22
5 / 5 pts
In order to encourage growth of a slow growing microbe what might a researcher do during a phase dilution streak? Your Answer:
LB media. All other options (A, C and D) are all forms of selective media, meaning they may potentially inhibit the growth of the unknown sample. The culture should be first expanded and then place onto selective/differential agar plates. Quiz Score: 98 out of 100
5/1/22, 6:14 PM M4: Module 4 Exam - Requires Respondus LockDown Browser + Webcam: Essential Microbiology with Lab-2021-Bowman https://nursingabc.instructure.com/courses/902/quizzes/23548?module_item_id=135785 1/
M4: Module 4 Exam - Requires Respondus LockDown
Browser + Webcam
Due No due date Points 100 Questions 24 Time Limit 60 Minutes
Requires Respondus LockDown Browser
Attempt History
Attempt Time Score LATEST Attempt 1 36 minutes 98 out of 100 Score for this quiz: 98 out of 100 Submitted Apr 21 at 9:47pm This attempt took 36 minutes. Question 1^2 / 2^ pts True or False: Differential media is best suited for distinguishing between two similar species of bacteria. Correct!Correct! True Growth media does not contain restrictive factors, while selective media is best used to encourage the growth of one microbe while simultaneously discouraging the growth of the other. Since two similar species of microbes are being studied they must be differentiated under similar but just slightly different conditions (differential media). False Question 2^2 / 2^ pts
5/1/22, 6:14 PM M4: Module 4 Exam - Requires Respondus LockDown Browser + Webcam: Essential Microbiology with Lab-2021-Bowman https://nursingabc.instructure.com/courses/902/quizzes/23548?module_item_id=135785 3/ True or False: LB agar is classified as a selective, non-differential media. True False Correct!Correct! LB agar is the most basic type of agar and like LB media supports the growth of virtually all microbes without restriction. Question 5^5 / 5^ pts Your Answer: What is agar used for in microbiology? Agar is used as a soft, smooth surface where microbes can be grown. Agar is used to create a solid, smooth surface on which microbes can grow. Question 6^2 / 2^ pts Blood agar is which type of medium? Select all that apply. Correct!Correct! Differential Blood agar can be used to differential between species based on its hemolytic activity.
5/1/22, 6:14 PM M4: Module 4 Exam - Requires Respondus LockDown Browser + Webcam: Essential Microbiology with Lab-2021-Bowman https://nursingabc.instructure.com/courses/902/quizzes/23548?module_item_id=135785 4/ Selective and Differential Correct!Correct! Enriched Selective Question 7^5 / 5^ pts Match the following hemolytic class with its description of activity.
- Alpha hemolysis A. No change.
- Beta hemolysis B. Greenish-brown color
- Gamma hemolysis C. Distinct zone of clearing Correct!Correct! (^1) B Correct!Correct! (^2) C 3 A Correct!Correct! Question 8^2 / 2^ pts Columbia CNA agar is used to isolate: Gram-Positive Correct!Correct!
5/1/22, 6:14 PM M4: Module 4 Exam - Requires Respondus LockDown Browser + Webcam: Essential Microbiology with Lab-2021-Bowman https://nursingabc.instructure.com/courses/902/quizzes/23548?module_item_id=135785 6/ No. A Gram stain would not be necessary, as only Gram- Negative microbes will grow on MacConkey agar. Question 11^10 / 10^ pts Your Answer: In an attempt to detect the presence of the pathogenic strain of E. coli O157:H7, a researcher spread a culture onto a MacConkey agar with failed results. What type of agar should they (correctly) try next? Why? The type of agar to be used would be SMAC agar (sorbitol MacConkey agar) this is the agar that is suitable to grow pathogenic strain of E. Coli because it cannor ferment sorbitol. The non-pathogenic strain of E. coli although can ferment both lactose and sorbitol hence, SMAC can be used as a differential agar to distinguish between them. The strain that is able to ferment sorbitol will be the non-pathogenic strain which will bring about an acidic Ph, on the other hand, the pathogenic strain is unable to ferment sorbitol and hence brings about a neutral to basic Ph. Thus, the pathogenic strain of E. coli 0157:H7 is able to be detected and distinguisehed as it does not ferment sorbitol The microbe should be plated on SMAC (Sorbitol-MacConkey agar) as it is specifically formulated to detect O157:H7. Pathogenic E. coli (O157:H7) cannot ferment sorbitol while non-pathogenic E. coli can ferment both soribitol and lactose. Therefore, colonies that ferment (acidic conditions; non- pathogenic) can be differentiated from non-fermenters (neutral to basic conditions; pathogenic).
5/1/22, 6:14 PM M4: Module 4 Exam - Requires Respondus LockDown Browser + Webcam: Essential Microbiology with Lab-2021-Bowman https://nursingabc.instructure.com/courses/902/quizzes/23548?module_item_id=135785 7/ Question 12^5 / 5^ pts Your Answer: In Eosin Methylene Blue (EMB) agar, what color indicates the presence of E. coli? Metallic Green Metallic Green Question 13^0 / 2^ pts Your Answer: Mannitol salt agar will turn what color in the presence of the pathogenic strain Staphylococcus aureus? Dark purple to black orrect Answerorrect Answer Yellow Pathogenic Staph aureus will turn the agar from red to yellow. Question 14^3 / 3^ pts What is the process of spreading a bacterial culture onto a petri dish called?
5/1/22, 6:14 PM M4: Module 4 Exam - Requires Respondus LockDown Browser + Webcam: Essential Microbiology with Lab-2021-Bowman https://nursingabc.instructure.com/courses/902/quizzes/23548?module_item_id=135785 9/ True Correct!Correct! To form a bacterial colony the initial cell must have multiplied many times over, often greater than a million, in order for the naked eye to resolve it. False Question 17^2 / 2^ pts True or False. The purpose of a quadrant streak is to expand a bacterial population. True Correct!Correct! False The purpose of the quadrant streak is to generate individual colonies such that a single (pure) bacterial sample can be isolated. Question 18^5 / 5^ pts Your Answer: To be considered a pure culture, the sample (1) can be traced back to a single cell and (2)__________? The sample must not contain external contaminats
5/1/22, 6:14 PM M4: Module 4 Exam - Requires Respondus LockDown Browser + Webcam: Essential Microbiology with Lab-2021-Bowman https://nursingabc.instructure.com/courses/902/quizzes/23548?module_item_id=135785 10/ The culture must also be free from external contaminants. Simply put, a pure sample would never contain multiple bacterial species (ie) Strep and Staph. Question 19^5 / 5^ pts Your Answer: A dilution gradient is formed when carrying out what generalize plating strategy? Quadrant streak (Phase dilution) A quadrant streak. The resulting gradient should always contain within it the growth of individual colonies. Question 20^5 / 5^ pts Your Answer: In what phase of a dilution streak would you expect to find the lowest concentration of bacteria, P2 or P4? P
