GSCU BACHOON MICROBIOLOGY TEST 2
EXAM 2025/2026 WITH ACTUAL CORRECT
QUESTIONS AND VERIFIED DETAILED
ANSWERS |CURRENTLY TESTING
QUESTIONS AND SOLUTIONS|ALREADY
GRADED A+|NEWEST|BRAND NEW VERSION
!!|GUARANTEED PASS
whats the most common form of sterilization
heat
T or F complete sterilization is required
false because because our bodies normal defenses can cope with a few microbes
Ex: from a drinking glass or surgical wound
what does commercial sterilization do for food products
processed so the colstridum botulim which is bacteria with endospores is destroyed
disinfection
- the destruction of non endospore forming pathogens on non living
- Ex: chemical, UV, boiling water, steam
antiseptic
- chemical to kill vegetative cells on living tissue
- some chemicals can be both, ex: alcohol, H2O2
degermation or degerming
mechanical removal rather than the killing of most of the microbes in a limited area
- Ex: swabbing skin with alcohol before injection
sanitization
- lower microbial numbers to safe levels and minimize the chances of disease
- ex: washing dishes
1|Page
,aseptic, asepsis
an object or area is free of pathogens
what factors influence the effectiveness of antimicrobial treatments?
1) # of microbes
2) microbial characteristics - type of cell wall, Gm+ or Gm-, endospores, capsules, etc...
3) environmental influences - water, soil, temp..
4) time of exposure
what type of cell wall is easier to kill (neg, endospores or positive)
gram neg
endospores are harder to kill
what type of treatment allows for microbes to die at a constant rate
disinfectant
disinfection and sterilization methods are typically divided into what?
1) physical methods
2) chemicals
3) radiation
1) physical methods
HEAT = dry heat and moist heat
- dry heat ex: flaming the loop and incineration
microbes heat resistance can be expanded by:
- thermal death point (TDP)
- thermal death time (TDT)
- decimal reduction time (DRT or D value
thermal death point
lowest temp in which all microbes in a liquid will be killed in 10 minutes
thermal death time
minimal length of time for all bacteria in a liquid to be killed
decimal reduction time
time in minutes in which 90% of a population of bacteria will be killed at a given temp.
2|Page
, what does boiling kill and what does it not kill?
- boiling for a few minutes kills most vegetative cells (ex: fungi, protozoa, viruses)
- it does NOT kill endospores (some endospores can resist boiling water for more than 20 hours)
autoclave
- most common way to sterilize
- moist heat under high pressure steam
- KILLS ENDOSPORES
pasteurization
- a method of control of heat and time of exposure
2 most widely used ways:
1) 63 deg. C/ 30 min.
2) 72-72.5 deg. C/ 15 sec.
- used for beer, wine, milk, etc....
what 3 goals are pasteurization methods designed to meet?
1) heat w/o loss of flavor or appearance
2) eliminate routine pathogens
3) increase shelf life of products
ultra high temp (UHT)
-uses super heated steam 140 deg. C for less than 1 second
=> yield products that will keep for weeks without refrigeration
filtration
- used for liquids
- it may not remove all viruses or bacteria
low temperature
- like refrigeration
- 0 deg. C - 7 deg. C
- are bacteriostatic, doesn't kill bacteria just stops it's growth
2) chemical methods
- Gm+ are more susceptible than Gm-
- few chemicals achieve sterility (few kill everything)
3|Page
EXAM 2025/2026 WITH ACTUAL CORRECT
QUESTIONS AND VERIFIED DETAILED
ANSWERS |CURRENTLY TESTING
QUESTIONS AND SOLUTIONS|ALREADY
GRADED A+|NEWEST|BRAND NEW VERSION
!!|GUARANTEED PASS
whats the most common form of sterilization
heat
T or F complete sterilization is required
false because because our bodies normal defenses can cope with a few microbes
Ex: from a drinking glass or surgical wound
what does commercial sterilization do for food products
processed so the colstridum botulim which is bacteria with endospores is destroyed
disinfection
- the destruction of non endospore forming pathogens on non living
- Ex: chemical, UV, boiling water, steam
antiseptic
- chemical to kill vegetative cells on living tissue
- some chemicals can be both, ex: alcohol, H2O2
degermation or degerming
mechanical removal rather than the killing of most of the microbes in a limited area
- Ex: swabbing skin with alcohol before injection
sanitization
- lower microbial numbers to safe levels and minimize the chances of disease
- ex: washing dishes
1|Page
,aseptic, asepsis
an object or area is free of pathogens
what factors influence the effectiveness of antimicrobial treatments?
1) # of microbes
2) microbial characteristics - type of cell wall, Gm+ or Gm-, endospores, capsules, etc...
3) environmental influences - water, soil, temp..
4) time of exposure
what type of cell wall is easier to kill (neg, endospores or positive)
gram neg
endospores are harder to kill
what type of treatment allows for microbes to die at a constant rate
disinfectant
disinfection and sterilization methods are typically divided into what?
1) physical methods
2) chemicals
3) radiation
1) physical methods
HEAT = dry heat and moist heat
- dry heat ex: flaming the loop and incineration
microbes heat resistance can be expanded by:
- thermal death point (TDP)
- thermal death time (TDT)
- decimal reduction time (DRT or D value
thermal death point
lowest temp in which all microbes in a liquid will be killed in 10 minutes
thermal death time
minimal length of time for all bacteria in a liquid to be killed
decimal reduction time
time in minutes in which 90% of a population of bacteria will be killed at a given temp.
2|Page
, what does boiling kill and what does it not kill?
- boiling for a few minutes kills most vegetative cells (ex: fungi, protozoa, viruses)
- it does NOT kill endospores (some endospores can resist boiling water for more than 20 hours)
autoclave
- most common way to sterilize
- moist heat under high pressure steam
- KILLS ENDOSPORES
pasteurization
- a method of control of heat and time of exposure
2 most widely used ways:
1) 63 deg. C/ 30 min.
2) 72-72.5 deg. C/ 15 sec.
- used for beer, wine, milk, etc....
what 3 goals are pasteurization methods designed to meet?
1) heat w/o loss of flavor or appearance
2) eliminate routine pathogens
3) increase shelf life of products
ultra high temp (UHT)
-uses super heated steam 140 deg. C for less than 1 second
=> yield products that will keep for weeks without refrigeration
filtration
- used for liquids
- it may not remove all viruses or bacteria
low temperature
- like refrigeration
- 0 deg. C - 7 deg. C
- are bacteriostatic, doesn't kill bacteria just stops it's growth
2) chemical methods
- Gm+ are more susceptible than Gm-
- few chemicals achieve sterility (few kill everything)
3|Page
