2026 QUESTIONS WITH SOLUTIONS GRADED
A+
◉ Sterilization. Answer: removal and killing of ALL microbes from
fomite (inanimate object)/organism
◉ Disinfection. Answer: inactivation/kill of microbes on fomites
◉ Sanitization. Answer: decrease of microbial load (amt. of microbes)
◉ Biological Safety Level. Answer: Levels of cleanliness assigned to
labs; CDC, NIH, WHO established 4 levels
◉ BSL-1. Answer: microbes aren't known to cause disease in healthy
host and pose minimal risk to workers and the environment
-sink for handwashing, door to close off lab (ex. freshman bio labs)
-ex. non-pathogenic strains of Escherichia coli
◉ BSL-2. Answer: microbes are typically indigenous and are associated
with diseases of varying severity; they pose moderate risk to workers
and the environment
, -BSL-1 and PPE, self-closing doors, eyewash station, autoclave, or
sterilization method (ex. Micro labs)
-ex. Staphylococcus aureus
◉ BSL-3. Answer: microbes are indigenous/exotic and cause lethal
diseases thru respiratory transmission
-BSL-2 and respirator, bio safety cabinets, hands-free wash sink, two
sets of doors (ex. none at UTA)
-ex. Mycobacterium tuberculosis
◉ BSL-4. Answer: - Microbes are dangerous & exotic, posing a
high risk of aerosol‐transmitted infections, which are frequently fatal
w/o treatment or vaccines. Few labs are at this level
-BSL-3 and full biohazard suit, shower on exit, lab must have own air
supply (only 13 in USA)
-ex. Ebola and Marburg viruses
◉ Levels of Clean in the Clinic: Critical. Answer: must be sterile; items
contact sterile tissue (i.e. blood)
◉ Levels of Clean in the Clinic: Semicritical. Answer: do not require
high level sterilization; items might contact sterile tissue (i.e. gut)