Page 1 of 33
GCSU (BACHOON) MICROBIOLOGY 2025/2026 TEST
2 EXAM CURRENTLY TESTING QUESTIONS AND
CORRECT DETAILED ANSWERS (VERIFIED) FOR
GUARANTEED PASS/TOP-RATED A+.
GCSU MICROBIOLOGY
Ace your GCSU Bachoon Microbiology Test 2 with this targeted
guide, designed to master foundational concepts including
microbial structure, metabolism, and classification. This
resource provides high-yield practice questions covering
essential lab techniques and pathogenic mechanisms.
Why do we study microbial growth? ...... ANSWER ....... 1)
to prove what causes disease
2) for antibiotic susceptibility (how to kill)
3) for research
what are the physical aspects of microbial growth? ......
ANSWER ....... - temperature
- pH
- osmotic pressure
, Page 2 of 33
what are the 3 main groups microbes are classified into
based on their optimum temperature? ...... ANSWER .......
1) psychrophiles
2) mesophiles
3) thermophiles
psychrophiles ...... ANSWER ....... - cold loving microbes
- don't cause disease
- (-10 deg. C to 20 deg. C)
what is a psychrotroph? ...... ANSWER ....... - organism
that is capable of growth between 0 deg. C and 30 deg. C
mesophiles ...... ANSWER ....... - moderate temperature
loving microbes, most common type
- (25 deg. C - 40 deg. C)
- these are human pathogens also include most of the
common spoilage and disease organisms.
- ex: 37 deg. C (the optimum temp. for many pathogenic
bacteria)
thermophiles ...... ANSWER ....... - heat loving microbes
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- (40 deg. C - 70 deg. C)
- many can't grow at temps below 45 deg. C
- hyperthermophiles = (70 deg. C - 110 deg. C)
what temperature do pathogens grow at? ...... ANSWER
....... - human body temp. (37 degrees celsius)
what pH range do most bacteria grow best in? ......
ANSWER ....... - a narrow pH range
- neutral (6.5 - 7.5)
- very few grow below pH 4
- foods with low pH (cheese, pickles..) don't spoil easily)
What are some examples of bacteria that grow below pH 4?
...... ANSWER ....... - sulfur oxidizers
- H. pylori
____ have more H+ than ______ ...... ANSWER ....... acids,
bases
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what is the osmotic pressure inside bacterial cells in an
isotonic solution? ...... ANSWER ....... - 0.85% NaCl
What type of solution inhibits bacterial growth? ......
ANSWER ....... - hypertonic solutions (solutes are higher
outside the cell)
- water leaves the cell
what is plasmolysis? ...... ANSWER ....... - the osmotic
loss of water from the cell in a hypertonic environment
- shrinkage of the cell plasma membrane - die
What causes high osmotic pressure and can be used to
preserve food? ...... ANSWER ....... - salt or sugar
- causes plasmolysis
ex: salted meat, jams, jelly
What percentage of salt and sugar are solutions that restrict
growth? ...... ANSWER ....... solutions that restrict
growth are:
> 5% salt
> 10% sugar
GCSU (BACHOON) MICROBIOLOGY 2025/2026 TEST
2 EXAM CURRENTLY TESTING QUESTIONS AND
CORRECT DETAILED ANSWERS (VERIFIED) FOR
GUARANTEED PASS/TOP-RATED A+.
GCSU MICROBIOLOGY
Ace your GCSU Bachoon Microbiology Test 2 with this targeted
guide, designed to master foundational concepts including
microbial structure, metabolism, and classification. This
resource provides high-yield practice questions covering
essential lab techniques and pathogenic mechanisms.
Why do we study microbial growth? ...... ANSWER ....... 1)
to prove what causes disease
2) for antibiotic susceptibility (how to kill)
3) for research
what are the physical aspects of microbial growth? ......
ANSWER ....... - temperature
- pH
- osmotic pressure
, Page 2 of 33
what are the 3 main groups microbes are classified into
based on their optimum temperature? ...... ANSWER .......
1) psychrophiles
2) mesophiles
3) thermophiles
psychrophiles ...... ANSWER ....... - cold loving microbes
- don't cause disease
- (-10 deg. C to 20 deg. C)
what is a psychrotroph? ...... ANSWER ....... - organism
that is capable of growth between 0 deg. C and 30 deg. C
mesophiles ...... ANSWER ....... - moderate temperature
loving microbes, most common type
- (25 deg. C - 40 deg. C)
- these are human pathogens also include most of the
common spoilage and disease organisms.
- ex: 37 deg. C (the optimum temp. for many pathogenic
bacteria)
thermophiles ...... ANSWER ....... - heat loving microbes
, Page 3 of 33
- (40 deg. C - 70 deg. C)
- many can't grow at temps below 45 deg. C
- hyperthermophiles = (70 deg. C - 110 deg. C)
what temperature do pathogens grow at? ...... ANSWER
....... - human body temp. (37 degrees celsius)
what pH range do most bacteria grow best in? ......
ANSWER ....... - a narrow pH range
- neutral (6.5 - 7.5)
- very few grow below pH 4
- foods with low pH (cheese, pickles..) don't spoil easily)
What are some examples of bacteria that grow below pH 4?
...... ANSWER ....... - sulfur oxidizers
- H. pylori
____ have more H+ than ______ ...... ANSWER ....... acids,
bases
, Page 4 of 33
what is the osmotic pressure inside bacterial cells in an
isotonic solution? ...... ANSWER ....... - 0.85% NaCl
What type of solution inhibits bacterial growth? ......
ANSWER ....... - hypertonic solutions (solutes are higher
outside the cell)
- water leaves the cell
what is plasmolysis? ...... ANSWER ....... - the osmotic
loss of water from the cell in a hypertonic environment
- shrinkage of the cell plasma membrane - die
What causes high osmotic pressure and can be used to
preserve food? ...... ANSWER ....... - salt or sugar
- causes plasmolysis
ex: salted meat, jams, jelly
What percentage of salt and sugar are solutions that restrict
growth? ...... ANSWER ....... solutions that restrict
growth are:
> 5% salt
> 10% sugar
