UIUC MCB 100 Exam 4 UPDATED ACTUAL Questions and CORRECT
Answers
Question: What is bio-safety level 1 and what are the precautions?
Correct Answer: handling pathogens that do not cause disease in healthy humans - hand-washing and
disinfecting surfaces, no eating
Question: What is bio-safety level 2 and what are the precautions?
Correct Answer: handling of moderately biohazardous agents in biosafety cabinets - use PPE, limited to
trained personnel, careful with sharps
Question: What are microbes considered biosafety level 2?
Correct Answer: bordetella pertussis (whooping cough), e. coli, salmonella, staphylococcus
Question: What is bio-safety level 3 and what are the precautions?
Correct Answer: handling of highly pathogenic, infectious, or toxic microbes in biosafety cabinets with
high PPE - HEPA filtered rooms, double-set doors to prevent air escape
Question: What are microbes considered biosafety level 3?
Correct Answer: anthrax, COVID, flu, TB, plague
Question: What is bio-safety level 4 and what are the precautions?
Correct Answer: handling of highly infectious pathogens that cause deadly disease with no treatments -
separate, isolated buildings, special PPE suits, airlocks, UV light rooms, pressurized
Question: _______ is the appropriate laboratory practices for conducting research with moderately
bio-hazardous microbes in biosafety cabinets while wearing proper PPE (personal protective equipment).
A. BSL5 B. BSL4 C. BSL3 D. BSL2 E. BSL1
Correct Answer: D
Question: Sterilization
Correct Answer: removal of all forms of life from object or fluid through chemicals, irradiation, high
pressure, or filtration. considered aseptic
Question: How is sterilization different from disinfection, sanitization, and pasteurization?
Correct Answer: Sterilization eradicates all microbes, the others just reduce the microbial load
Question: What are natural agents for disinfection?
Correct Answer: antibiotics, natural acids like vinegar, alcohols
Question: What are chemical agents for disinfection?
Correct Answer: chemicals, drugs, detergents, gases
Question: What can be used externally on inanimate objects?
Correct Answer: disinfectants and sanitizers
Question: What can be used on body surfaces?
Correct Answer: antiseptics and germicides
, Question: What can be used internally/ingested?
Correct Answer: antibiotics, antimicrobials
Question: What are anti-microbials?
Correct Answer: substances that kill or inhibit the growth of microbes such as bacteria, fungi, or parasites
microbicidal vs. microbiostatic
Question: What are microbiocidals?
Correct Answer: germicidals that lyse and kill bacteria (can potentially release toxins)
Question: What are microbiostatics?
Correct Answer: prevents the growth of microbes but does not kill it, bacteria can recover and regrow
when antibiotics stop
Question: Which of the following is bacteriostatic? A. heating in an oven at 171°C for an hour B. filtering
through a 0.2 µm membrane C. freezing below 0°C for 10 minutes D. bleaching for an hour E. boiling for
an hour
Correct Answer: C
Question: What is microbial death?
Correct Answer: the permanent loss of reproductive ability under ideal environmental conditions
Question: What is microbial death rate?
Correct Answer: often a constant rate for any given microbe under a particular set of conditions
Question: What are D-values?
Correct Answer: the amount of time it takes for each round of 90% killing to occur (1 D-value = 90%, 2
D-value = 99%, 3 D-value = 99.9%)
Question: A particular sterilization process takes 60 minutes to kill all organisms in a sample with 10 6
microbes. How long does it take to eliminate 99.99% (4 D-values) of the organisms using this process? A.
10 minutes B. 20 minutes C. 30 minutes D. 40 minutes E. 50 minutes
Correct Answer: D
Question: What is filtration method best used for?
Correct Answer: used for heat-sensitive solutions that can't be heat-sterilized, such as Botox
Question: What is filtration method?
Correct Answer: passing fluid through a filter with a pore size of 0.2 micrometers
Question: What is pasteurization?
Correct Answer: the application of a high heat for a short time to kill harmful bacteria in beverages
Question: What is dry heating/baking?
Correct Answer: involves conduction, heating the exterior of surface to eventually heat completely to
desired temp (typically 150 c for 2 hours)
Question: Boiling for 30 minutes will not kill which organisms?
Correct Answer: it will kill almost all vegetative bacterial cells, but not spores
Answers
Question: What is bio-safety level 1 and what are the precautions?
Correct Answer: handling pathogens that do not cause disease in healthy humans - hand-washing and
disinfecting surfaces, no eating
Question: What is bio-safety level 2 and what are the precautions?
Correct Answer: handling of moderately biohazardous agents in biosafety cabinets - use PPE, limited to
trained personnel, careful with sharps
Question: What are microbes considered biosafety level 2?
Correct Answer: bordetella pertussis (whooping cough), e. coli, salmonella, staphylococcus
Question: What is bio-safety level 3 and what are the precautions?
Correct Answer: handling of highly pathogenic, infectious, or toxic microbes in biosafety cabinets with
high PPE - HEPA filtered rooms, double-set doors to prevent air escape
Question: What are microbes considered biosafety level 3?
Correct Answer: anthrax, COVID, flu, TB, plague
Question: What is bio-safety level 4 and what are the precautions?
Correct Answer: handling of highly infectious pathogens that cause deadly disease with no treatments -
separate, isolated buildings, special PPE suits, airlocks, UV light rooms, pressurized
Question: _______ is the appropriate laboratory practices for conducting research with moderately
bio-hazardous microbes in biosafety cabinets while wearing proper PPE (personal protective equipment).
A. BSL5 B. BSL4 C. BSL3 D. BSL2 E. BSL1
Correct Answer: D
Question: Sterilization
Correct Answer: removal of all forms of life from object or fluid through chemicals, irradiation, high
pressure, or filtration. considered aseptic
Question: How is sterilization different from disinfection, sanitization, and pasteurization?
Correct Answer: Sterilization eradicates all microbes, the others just reduce the microbial load
Question: What are natural agents for disinfection?
Correct Answer: antibiotics, natural acids like vinegar, alcohols
Question: What are chemical agents for disinfection?
Correct Answer: chemicals, drugs, detergents, gases
Question: What can be used externally on inanimate objects?
Correct Answer: disinfectants and sanitizers
Question: What can be used on body surfaces?
Correct Answer: antiseptics and germicides
, Question: What can be used internally/ingested?
Correct Answer: antibiotics, antimicrobials
Question: What are anti-microbials?
Correct Answer: substances that kill or inhibit the growth of microbes such as bacteria, fungi, or parasites
microbicidal vs. microbiostatic
Question: What are microbiocidals?
Correct Answer: germicidals that lyse and kill bacteria (can potentially release toxins)
Question: What are microbiostatics?
Correct Answer: prevents the growth of microbes but does not kill it, bacteria can recover and regrow
when antibiotics stop
Question: Which of the following is bacteriostatic? A. heating in an oven at 171°C for an hour B. filtering
through a 0.2 µm membrane C. freezing below 0°C for 10 minutes D. bleaching for an hour E. boiling for
an hour
Correct Answer: C
Question: What is microbial death?
Correct Answer: the permanent loss of reproductive ability under ideal environmental conditions
Question: What is microbial death rate?
Correct Answer: often a constant rate for any given microbe under a particular set of conditions
Question: What are D-values?
Correct Answer: the amount of time it takes for each round of 90% killing to occur (1 D-value = 90%, 2
D-value = 99%, 3 D-value = 99.9%)
Question: A particular sterilization process takes 60 minutes to kill all organisms in a sample with 10 6
microbes. How long does it take to eliminate 99.99% (4 D-values) of the organisms using this process? A.
10 minutes B. 20 minutes C. 30 minutes D. 40 minutes E. 50 minutes
Correct Answer: D
Question: What is filtration method best used for?
Correct Answer: used for heat-sensitive solutions that can't be heat-sterilized, such as Botox
Question: What is filtration method?
Correct Answer: passing fluid through a filter with a pore size of 0.2 micrometers
Question: What is pasteurization?
Correct Answer: the application of a high heat for a short time to kill harmful bacteria in beverages
Question: What is dry heating/baking?
Correct Answer: involves conduction, heating the exterior of surface to eventually heat completely to
desired temp (typically 150 c for 2 hours)
Question: Boiling for 30 minutes will not kill which organisms?
Correct Answer: it will kill almost all vegetative bacterial cells, but not spores
