,BIOD 171 Essential Microbiology – Lab 1 Exam (100 Q&A)
Section 1: Laboratory Safety & Aseptic Technique (Q1-20)
1. What is the primary purpose of practicing aseptic technique?
A) To make experiments more complicated
B) To ensure rapid bacterial growth
C) To prevent contamination of cultures and the environment
D) To reduce the need for cleaning
2. Which biosafety level (BSL) is appropriate for working with microbes like E. coli K-12 (non-
pathogenic strain)?
A) BSL-1
B) BSL-1
C) BSL-3
D) BSL-4
3. How should you properly dispose of used bacterial culture plates?
A) In the regular trash
B) In a designated biohazard autoclave bag
C) Down the sink with bleach
D) Leave them on the bench for the instructor
4. What must you always wear when working in the microbiology lab, even during non-sterile
steps?
A) Safety goggles
B) Lab coat
C) Face shield
D) All of the above
5. After a spill of a live bacterial culture, the first step is to:
A) Run for help
B) Hide it
C) Notify the instructor immediately
D) Wipe it up with dry paper towels
6. The process of using an open flame (e.g., Bunsen burner) to create a sterile field primarily
works by:
A) Creating light to see better
,B) Creating an upward convection current that prevents airborne contaminants from settling
C) Heating the entire room
D) Killing all bacteria on the bench
7. When flaming an inoculating loop, how long should you hold it in the hottest part of the
flame?
A) 1 second
B) Until the entire loop glows red-hot (5-10 seconds)
C) 30 seconds
D) Just pass it quickly
8. Which of these is NOT part of proper aseptic transfer technique?
A) Working close to the flame
B) Flaming tube lids before and after transfer
C) Holding tube lids in your mouth to free both hands
D) Cooling the loop before touching the culture
9. True or False: It is acceptable to eat and drink in the lab if you are very careful.
A) True
B) False
10. When should you disinfect your lab bench?
A) Only at the end of the semester
B) At the beginning and end of every lab session
C) Only if you spill something
D) Never; it’s the janitor’s job
11. What does the term “sterile” mean?
A) Slightly clean
B) Free from most bacteria
C) Completely free of all viable microorganisms, including spores
D) Treated with soap
12. What is the correct way to label a petri dish?
A) On the lid in marker
B) On the bottom (agar side) around the edge
C) On a separate piece of tape
D) On the lid in pencil
13. You should never lay a contaminated inoculating loop on the bench because:
A) It might get lost
, B) It will contaminate the surface and potentially yourself
C) It’s expensive
D) It cools down too fast
14. The purpose of flaming the neck of a culture tube after removing the lid is to:
A) Dry it
B) Kill any airborne microbes that may have settled
C) Melt the glass
D) Seal it shut
15. Which direction should you open a petri dish when working?
A) Fully open like a book
B) Crack it open just enough to insert your tool, keeping lid over the agar
C) Remove the lid completely and set it aside
D) Invert it completely
16. Hand washing in the lab should be performed:
A) Only at the end of the day
B) Before leaving the lab, even if you wore gloves
C) Only if you feel dirty
D) Instead of wearing gloves
17. If your Bunsen burner flame is yellow and flickering, it is:
A) Perfectly fine
B) Too hot
C) A “cool” or “luminous” flame, indicating incomplete combustion (adjust air intake)
D) Out of gas
18. The most effective way to decontaminate media, tools, and waste in a microbiology lab is:
A) Bleach soak
B) UV light
C) Autoclaving (steam sterilization under pressure)
D) Dishwasher
19. What is the primary hazard associated with using a Bunsen burner?
A) Electric shock
B) Open flame and risk of burns/fire
C) Toxic fumes
D) Loud noise
Section 1: Laboratory Safety & Aseptic Technique (Q1-20)
1. What is the primary purpose of practicing aseptic technique?
A) To make experiments more complicated
B) To ensure rapid bacterial growth
C) To prevent contamination of cultures and the environment
D) To reduce the need for cleaning
2. Which biosafety level (BSL) is appropriate for working with microbes like E. coli K-12 (non-
pathogenic strain)?
A) BSL-1
B) BSL-1
C) BSL-3
D) BSL-4
3. How should you properly dispose of used bacterial culture plates?
A) In the regular trash
B) In a designated biohazard autoclave bag
C) Down the sink with bleach
D) Leave them on the bench for the instructor
4. What must you always wear when working in the microbiology lab, even during non-sterile
steps?
A) Safety goggles
B) Lab coat
C) Face shield
D) All of the above
5. After a spill of a live bacterial culture, the first step is to:
A) Run for help
B) Hide it
C) Notify the instructor immediately
D) Wipe it up with dry paper towels
6. The process of using an open flame (e.g., Bunsen burner) to create a sterile field primarily
works by:
A) Creating light to see better
,B) Creating an upward convection current that prevents airborne contaminants from settling
C) Heating the entire room
D) Killing all bacteria on the bench
7. When flaming an inoculating loop, how long should you hold it in the hottest part of the
flame?
A) 1 second
B) Until the entire loop glows red-hot (5-10 seconds)
C) 30 seconds
D) Just pass it quickly
8. Which of these is NOT part of proper aseptic transfer technique?
A) Working close to the flame
B) Flaming tube lids before and after transfer
C) Holding tube lids in your mouth to free both hands
D) Cooling the loop before touching the culture
9. True or False: It is acceptable to eat and drink in the lab if you are very careful.
A) True
B) False
10. When should you disinfect your lab bench?
A) Only at the end of the semester
B) At the beginning and end of every lab session
C) Only if you spill something
D) Never; it’s the janitor’s job
11. What does the term “sterile” mean?
A) Slightly clean
B) Free from most bacteria
C) Completely free of all viable microorganisms, including spores
D) Treated with soap
12. What is the correct way to label a petri dish?
A) On the lid in marker
B) On the bottom (agar side) around the edge
C) On a separate piece of tape
D) On the lid in pencil
13. You should never lay a contaminated inoculating loop on the bench because:
A) It might get lost
, B) It will contaminate the surface and potentially yourself
C) It’s expensive
D) It cools down too fast
14. The purpose of flaming the neck of a culture tube after removing the lid is to:
A) Dry it
B) Kill any airborne microbes that may have settled
C) Melt the glass
D) Seal it shut
15. Which direction should you open a petri dish when working?
A) Fully open like a book
B) Crack it open just enough to insert your tool, keeping lid over the agar
C) Remove the lid completely and set it aside
D) Invert it completely
16. Hand washing in the lab should be performed:
A) Only at the end of the day
B) Before leaving the lab, even if you wore gloves
C) Only if you feel dirty
D) Instead of wearing gloves
17. If your Bunsen burner flame is yellow and flickering, it is:
A) Perfectly fine
B) Too hot
C) A “cool” or “luminous” flame, indicating incomplete combustion (adjust air intake)
D) Out of gas
18. The most effective way to decontaminate media, tools, and waste in a microbiology lab is:
A) Bleach soak
B) UV light
C) Autoclaving (steam sterilization under pressure)
D) Dishwasher
19. What is the primary hazard associated with using a Bunsen burner?
A) Electric shock
B) Open flame and risk of burns/fire
C) Toxic fumes
D) Loud noise
