University of Waterloo
Fundamentals of Microbiology
)
Pages Total Marks Section Questions
Section 1 Multiple
10 Choice 10 questions 20 total marks
Section 2 Short Answer 5 questions 20 total marks
Section 3 True/False 10 questions 10 total marks
Name Student ID
Date Signature
How to use this exam
1 Set a timer. Practice under real exam conditions! No notes, no AI assistance.
2 When finished, scan the QR code on the last page to submit and see the correct answers with
detailed explanations.
3 Review your mistakes carefully and note down areas that need improvement. Use Studocu AI to
create targeted study materials like quizzes, summaries, and study guides.
, Section 1/3 20 total marks
Multiple Choice
Select the single best answer for each question. Each question is worth 2 marks.
Question 1 20 total marks
A student in the laboratory is tasked with identifying an unknown bacterial culture. They perform a stan-dard Gram
stain procedure and observe the sample under a bright-field compound light microscope using the 100x
objective lens with immersion oil. The student notes that the cells appear as purple spheres arranged in grape-
like clusters. The microscope being used has an ocular lens magnification of 10x and a numerical aperture (NA)
of 1.25 for the objective lens.
A What is the total magnification of the sample as observed by the student in the scenario provided?
A 110x
B 1000x
C 100x
D 10000x
B Based on the color observed after the Gram stain, what can be inferred about the cell wall structure
of this unknown culture?
A The cells lack peptidoglycan entirely and use pseudomurein.
B The cells have a high concentration of mycolic acids in their cell wall.
C The cells have a thin layer of peptidoglycan and an outer membrane.
D The cells have a thick layer of peptidoglycan and lack an outer membrane.
C Why was immersion oil required for the student to achieve a clear image at 1000x total magni-fication?
A To increase the magnification beyond the limit of the lenses.
B To provide contrast by staining the background of the slide.
C To decrease the numerical aperture of the objective lens.
D To prevent the refraction of light as it passes from glass to air.
Fundamentals of Microbiology
)
Pages Total Marks Section Questions
Section 1 Multiple
10 Choice 10 questions 20 total marks
Section 2 Short Answer 5 questions 20 total marks
Section 3 True/False 10 questions 10 total marks
Name Student ID
Date Signature
How to use this exam
1 Set a timer. Practice under real exam conditions! No notes, no AI assistance.
2 When finished, scan the QR code on the last page to submit and see the correct answers with
detailed explanations.
3 Review your mistakes carefully and note down areas that need improvement. Use Studocu AI to
create targeted study materials like quizzes, summaries, and study guides.
, Section 1/3 20 total marks
Multiple Choice
Select the single best answer for each question. Each question is worth 2 marks.
Question 1 20 total marks
A student in the laboratory is tasked with identifying an unknown bacterial culture. They perform a stan-dard Gram
stain procedure and observe the sample under a bright-field compound light microscope using the 100x
objective lens with immersion oil. The student notes that the cells appear as purple spheres arranged in grape-
like clusters. The microscope being used has an ocular lens magnification of 10x and a numerical aperture (NA)
of 1.25 for the objective lens.
A What is the total magnification of the sample as observed by the student in the scenario provided?
A 110x
B 1000x
C 100x
D 10000x
B Based on the color observed after the Gram stain, what can be inferred about the cell wall structure
of this unknown culture?
A The cells lack peptidoglycan entirely and use pseudomurein.
B The cells have a high concentration of mycolic acids in their cell wall.
C The cells have a thin layer of peptidoglycan and an outer membrane.
D The cells have a thick layer of peptidoglycan and lack an outer membrane.
C Why was immersion oil required for the student to achieve a clear image at 1000x total magni-fication?
A To increase the magnification beyond the limit of the lenses.
B To provide contrast by staining the background of the slide.
C To decrease the numerical aperture of the objective lens.
D To prevent the refraction of light as it passes from glass to air.
