STRAIGHTERLINE MICROBIOLOGY
ACTUAL EXAM PAPER 2026
QUESTIONS WITH ANSWERS GRADED
A+
◍ Define the concept of universal precautions (short answer).
Answer: Universal precautions means any and all samples, whether known
or unknown, are to be treated as potentially hazardous (or pathogenic)
materials
◍ motility.
Answer: semisolid media shows what?
◍ List at lease 3 observations a researcher would be sure to note while
assessing and unknown microbial sample (short answer).
Answer: Need to note:1. Size and shape2. Any observable motility3. Gram
status (positive or negative)
◍ While observing an unknown sample of limited amounts, a researcher must
determine the following observations: 1) the presence of any motility and 2)
its Gram status using the same sample- the liquid sample cannot be divided.
Which would you determine first and why? (short answer).
Answer: You must determine motility before determining Gram status.
Motility requires a wet mount, while gram staining requires heat fixing the
sample. If one were to begin with the gram stain, the heat fixation process
would kill the organism, making any observations regarding motility
impossible. The correct approach would be to place the liquid culture on a
glass slide and determine its motility status. Next, the same liquid culture
can be heat fixed and gram stained.
,◍ A facultative anaerobe is a microorganism capable of growth under what
conditions? (short answer).
Answer: A facultative anaerobe is capable of growth under aerobic (with
oxygen) and anaerobic (without oxygen) conditions
◍ isolating/culturing bacteria.
Answer: solid media is best for?
◍ True or False: The Lancefield groups are used to subdivide antigenic groups
of alpha-hemolytic Streptococcus.
Answer: False. The Lancefield groups are used to subdivide beta-hemolytic
strep
◍ synthetic; defined.
Answer: What are the terms for a media whose exact chemical compositions
are known?
◍ differential media.
Answer: allows growth of several types of microbes and displays visible
differences among those microbes
◍ selective media.
Answer: suppress unwanted microbes and encourage desired microbes
◍ The distinctions for Lancefield subgroups lie in its: (select all that apply)
A. Catalase activity
B. Carbohydrate composition of antigens
C. Hemolytic activity
D. All of the above.
Answer: B. Carbohydrate composition of antigens
◍ Rheumatic fever displays _____ hemolytic activity and occurs when _____
if left untreated.
Answer: Beta: strep. Pharyngitis
◍ reducing media.
Answer: a culture medium containing ingredients that will remove dissolved
, oxygen from the medium to allow the growth of anaerobes
◍ True or False: Under most circumstances, staphylococcus can be found in
~80% of human population where it remains non-symptomatic.
Answer: False. Staphylococcus in only found (non-symptomatic) in ~30%
of the human population
◍ transport media.
Answer: used to maintain and preserve specimens that have to be held for a
period of time before clinical analysis
◍ assay media.
Answer: used to test the effectiveness of antimicrobial drugs
◍ Define commensal bacteria (short answer) (know term and definition first).
Answer: The bacterium neither harms nor benefits from the host from which
it obtains nutrients
◍ enumeration media.
Answer: used by industrial and environmental microbiologists to count the
numbers of organisms in milk, water, food, soil, and other samples
◍ inoculation, incubation, isolation, inspection, identification.
Answer: What are the five I's of microbiology?
◍ How can staphylococcus be differentially tested? (short answer).
Answer: Staphylococcus species are capable of growth in the presence of
bile salts
◍ innoculating loop.
Answer: used to transfer bacteria from one place to another
◍ Symptoms of folliculitis.
Answer: Pus-filled lesions on skin or hair
◍ pure culture.
Answer: a culture containing a single kind of microorganism
◍ Symptoms of scalded-skin syndrome.
, Answer: Ruptured-pustules; treated with penicilin
◍ mixed culture.
Answer: microbial culture consisting of two or more species
◍ Symptoms of Impetigo.
Answer: Childhood skin disease near mouth/nose
◍ Symptoms of conjuctivitis.
Answer: Infections of thin, transparent scieral tissue
◍ dark field.
Answer: What microscope has an image that is brightly illuminated
specimens surrounded by a black field.
◍ phase-contrast.
Answer: which microscope is used for observing intracellular structures
such as bacterial spores, granules, and organelles, as well as the locomotor
structures of eukaryotic cells such as cilia. (in black-and-white)
◍ Symptoms of ophthalmia neonatorum.
Answer: Infection occurs at time of birth
◍ True or False: the causative agent of conjunctivitis can be either bacterial or
viral.
Answer: True. There are bacterial (staph) and viral forms of conjunctivitis,
both resulting in the inflammation of the conjunctiva and 'pink eye'
◍ True or False: Tuberculosis is best identified by a gram stain.
Answer: False. Mycobacterium show poor Gram staining and show be
screened via an acid-fast stain
◍ True or False: You can become infected with TB simply by sharing a drink
with someone who is currently infected with TB.
Answer: False. As per the CDC guidelines, simply shaking someone's hand,
sharing a drink, or even kissing someone cannot spread TB
◍ Identify the disease based on the following (select all that apply): It is a
small, acid-fast rod usually remaining asymptomatic for up to 20 years. It
ACTUAL EXAM PAPER 2026
QUESTIONS WITH ANSWERS GRADED
A+
◍ Define the concept of universal precautions (short answer).
Answer: Universal precautions means any and all samples, whether known
or unknown, are to be treated as potentially hazardous (or pathogenic)
materials
◍ motility.
Answer: semisolid media shows what?
◍ List at lease 3 observations a researcher would be sure to note while
assessing and unknown microbial sample (short answer).
Answer: Need to note:1. Size and shape2. Any observable motility3. Gram
status (positive or negative)
◍ While observing an unknown sample of limited amounts, a researcher must
determine the following observations: 1) the presence of any motility and 2)
its Gram status using the same sample- the liquid sample cannot be divided.
Which would you determine first and why? (short answer).
Answer: You must determine motility before determining Gram status.
Motility requires a wet mount, while gram staining requires heat fixing the
sample. If one were to begin with the gram stain, the heat fixation process
would kill the organism, making any observations regarding motility
impossible. The correct approach would be to place the liquid culture on a
glass slide and determine its motility status. Next, the same liquid culture
can be heat fixed and gram stained.
,◍ A facultative anaerobe is a microorganism capable of growth under what
conditions? (short answer).
Answer: A facultative anaerobe is capable of growth under aerobic (with
oxygen) and anaerobic (without oxygen) conditions
◍ isolating/culturing bacteria.
Answer: solid media is best for?
◍ True or False: The Lancefield groups are used to subdivide antigenic groups
of alpha-hemolytic Streptococcus.
Answer: False. The Lancefield groups are used to subdivide beta-hemolytic
strep
◍ synthetic; defined.
Answer: What are the terms for a media whose exact chemical compositions
are known?
◍ differential media.
Answer: allows growth of several types of microbes and displays visible
differences among those microbes
◍ selective media.
Answer: suppress unwanted microbes and encourage desired microbes
◍ The distinctions for Lancefield subgroups lie in its: (select all that apply)
A. Catalase activity
B. Carbohydrate composition of antigens
C. Hemolytic activity
D. All of the above.
Answer: B. Carbohydrate composition of antigens
◍ Rheumatic fever displays _____ hemolytic activity and occurs when _____
if left untreated.
Answer: Beta: strep. Pharyngitis
◍ reducing media.
Answer: a culture medium containing ingredients that will remove dissolved
, oxygen from the medium to allow the growth of anaerobes
◍ True or False: Under most circumstances, staphylococcus can be found in
~80% of human population where it remains non-symptomatic.
Answer: False. Staphylococcus in only found (non-symptomatic) in ~30%
of the human population
◍ transport media.
Answer: used to maintain and preserve specimens that have to be held for a
period of time before clinical analysis
◍ assay media.
Answer: used to test the effectiveness of antimicrobial drugs
◍ Define commensal bacteria (short answer) (know term and definition first).
Answer: The bacterium neither harms nor benefits from the host from which
it obtains nutrients
◍ enumeration media.
Answer: used by industrial and environmental microbiologists to count the
numbers of organisms in milk, water, food, soil, and other samples
◍ inoculation, incubation, isolation, inspection, identification.
Answer: What are the five I's of microbiology?
◍ How can staphylococcus be differentially tested? (short answer).
Answer: Staphylococcus species are capable of growth in the presence of
bile salts
◍ innoculating loop.
Answer: used to transfer bacteria from one place to another
◍ Symptoms of folliculitis.
Answer: Pus-filled lesions on skin or hair
◍ pure culture.
Answer: a culture containing a single kind of microorganism
◍ Symptoms of scalded-skin syndrome.
, Answer: Ruptured-pustules; treated with penicilin
◍ mixed culture.
Answer: microbial culture consisting of two or more species
◍ Symptoms of Impetigo.
Answer: Childhood skin disease near mouth/nose
◍ Symptoms of conjuctivitis.
Answer: Infections of thin, transparent scieral tissue
◍ dark field.
Answer: What microscope has an image that is brightly illuminated
specimens surrounded by a black field.
◍ phase-contrast.
Answer: which microscope is used for observing intracellular structures
such as bacterial spores, granules, and organelles, as well as the locomotor
structures of eukaryotic cells such as cilia. (in black-and-white)
◍ Symptoms of ophthalmia neonatorum.
Answer: Infection occurs at time of birth
◍ True or False: the causative agent of conjunctivitis can be either bacterial or
viral.
Answer: True. There are bacterial (staph) and viral forms of conjunctivitis,
both resulting in the inflammation of the conjunctiva and 'pink eye'
◍ True or False: Tuberculosis is best identified by a gram stain.
Answer: False. Mycobacterium show poor Gram staining and show be
screened via an acid-fast stain
◍ True or False: You can become infected with TB simply by sharing a drink
with someone who is currently infected with TB.
Answer: False. As per the CDC guidelines, simply shaking someone's hand,
sharing a drink, or even kissing someone cannot spread TB
◍ Identify the disease based on the following (select all that apply): It is a
small, acid-fast rod usually remaining asymptomatic for up to 20 years. It
