BIOL 203 MICROBIOLOGY LCC FINAL /BIOL
203 MICROBIOLOGY LCC FINAL EXAM PREP
(2 LATEST VERSIONS) 2025/2026 WITH
ACTUAL CORRECT QUESTIONS AND
VERIFIED DETAILED ANSWERS
|FREQUENTLY TESTED QUESTIONS AND
SOLUTION|ALREADY GRADED
A+|NEWEST|BRAND NEW VERSION
!!|GUARANTEED PASS
Consider obligate anaerobes, facultative anaerobes, and aerotolerant anaerobes. In what way
are they all similar? In what way are they all different? Be specific and explain your answer for
full credit.
They are similar by all having to do with living with oxygen, good or bad.
They are different because obligate anaerobes cannot survive with oxygen, facultative
anaerobes use oxygen to grow but can also live without it, and aerotolerant anaerobes don't
use oxygen but can still live with it.
Humans live symbiotically with many, many different microbes. Describe a human-microbe
relationship that is considered mutualistic and then describe one that is considered parasitic.
A human-microbe relationship that is considered mutalistic is bacteria, they can prevent
pathogenic organisms from taking over an area, while the human offers them a place to live and
survive.
A human-microbe relationship that is considered parasitic is parasitism, this relationship harms
the host and is beneficial to the parasite. The kinds of harm can be anywhere from superficial
damage, rapid damage, to significant damage.
There are microbes that call your intestines home. Using the terms you learned in this unit, we
might describe them as obligate anaerobes, alkaliphiles, mesophiles, etc. There are microbes
1|Page
,that call your skin home. Use at least 3-4 terms from this unit to describe skin microbes and
explain why you selected each term.
What do we call bacteria that grow at those temperatures?
Human skin is very salty (from sweat) so skin microbes could be called halophiles.
The skin is exposed to oxygen in our atmosphere so skin microbes could be obligate aerobes,
facultative anaerobes, or possibly aerotolerant anaerobes.
The skin is slightly acidic (from oil or sebum) so skin microbes could be acidophiles.
The skin is body temperature (37 degrees Celsius) or slightly below so skin microbes could be
mesophiles.
Skin microbes live in close association with humans so they could be called symbiotic.
Skin microbes are considered part of our normal microbiota that benefit us by preventing
transient pathogen colonization while we provide them with shelter and food so they could be
considered mutualistic.
In what phase of microbial growth are cells doubling at the fastest rate?
Log
In what phase of cell growth is the rate of growth or doubling of cells equal to the rate of death
of cell?
Stationary
In this stage of microbial growth, when transfered from one medium to another, we don't see
an increase in numbers. Rather we know that the microorganisms are metabolically active and
getting used to the environment.
Lag
2|Page
,In this stage of microbial growth, waste products of metabolism have built up and nutrients
have been depleted leading to rapid death of the cells.
Death
This class of bacteria thrive in very cold temperatures.
Psychrophiles
These bacteria require hydrostatic pressure to keep their enzymes in the correct conformation
for reactivity.
Barophiles
The bacteria in your stomach are likely these types of bacteria.
Acidophiles
Halophiles are likely to be found in fresh water lakes.
False
Bacterial growth is defined by an increase in cell
number
The molecule passes from one side of the membrane with no assistance via protein or ATP. It is
naturally traveling from an area of high concentration to low concentration
Diffusion
Water passes through the membrane from an area of high water concentration (low solute
concentration) to an area of low water concentration (high solute concentration.)
Osmosis
A molecule passes through a membrane with the help of a carrier protein. No ATP is involved
and it travels from an area of high concentration to low concentration, but the molecule is too
large, bulky, polar, or charged and cannot pass through the phospholipid portion of the
membrane.
Facilitated diffusion
Special solute binding proteins pick up the molecule and bring them to a tranporter protein
located in the membrane. ATP is used to pump the molecule through the transporter protein.
Carrier Mediated
3|Page
, A molecule is captured by a protein carrier and modified as it passes through the membrane.
Group Translocation
The entire membrane makes a pocket and eventual vesicle and any molecules that are bound to
the surface are brought inside the cell.
Endocytosis
You set up two cultures with an equal amounts of Escherichia coli. You label one culture "A" and
the other "B." Each culture is given 100mL of tryptic soy nutrient broth. You then take culture A
and incubate it in the absence of oxygen and take culture B and incubate it in the presence of
oxygen for one week. If E. coli is able to use both aerobic and anaerobic metabolism, the how
would we classify it? Is it an obligate aerobe, obligate anaerobe, or a facultative anaerobe?
Based on that information, which flask, A or B, would have more cells at the end of the week?
Fully explain your answer.
If they have the same amount of nutrients, the flask with oxygen will use them more efficiently
and produce more ATP which will allow more growth.
E. coli would be classified as a facultative anaerobe because it is capable of both aerobic and
anaerobic metabolic pathways.
Both cultures would grow. Culture A in the absence of oxygen would produce only 2ATP per
glucose. Culture B in the presence of oxygen would produce 38ATP per glucose. ATP is used by
to cell to do "cell work" which would include anabolic or building reactions like making new cell
components for binary fission and cell growth to occur. So the more ATP available, the more
growth. Both cultures started with the same amount of TSB and so the same amount of glucose.
The culture that was more efficient at extracting ATP (38 vs 2) per glucose molecule would be
the culture with the most growth.
Culture B would have more growth.
What is NAD (NAD+) and NADH? Describe them as if you were a chemist. Why is NAD needed
by all cells no matter what type of metabolism they use?
NAD or nicotinamide adenine dinulecotide, is a coenzyme, which is a substance that is needed
for all the enzymes that are in the body. It is used to start the Electron Transport Chain.
NADH or ninoctinamide adenine dinulecotide plus hydrogen, is a coenzyme and helps in the
chemical process that generates energy to the body.
4|Page
203 MICROBIOLOGY LCC FINAL EXAM PREP
(2 LATEST VERSIONS) 2025/2026 WITH
ACTUAL CORRECT QUESTIONS AND
VERIFIED DETAILED ANSWERS
|FREQUENTLY TESTED QUESTIONS AND
SOLUTION|ALREADY GRADED
A+|NEWEST|BRAND NEW VERSION
!!|GUARANTEED PASS
Consider obligate anaerobes, facultative anaerobes, and aerotolerant anaerobes. In what way
are they all similar? In what way are they all different? Be specific and explain your answer for
full credit.
They are similar by all having to do with living with oxygen, good or bad.
They are different because obligate anaerobes cannot survive with oxygen, facultative
anaerobes use oxygen to grow but can also live without it, and aerotolerant anaerobes don't
use oxygen but can still live with it.
Humans live symbiotically with many, many different microbes. Describe a human-microbe
relationship that is considered mutualistic and then describe one that is considered parasitic.
A human-microbe relationship that is considered mutalistic is bacteria, they can prevent
pathogenic organisms from taking over an area, while the human offers them a place to live and
survive.
A human-microbe relationship that is considered parasitic is parasitism, this relationship harms
the host and is beneficial to the parasite. The kinds of harm can be anywhere from superficial
damage, rapid damage, to significant damage.
There are microbes that call your intestines home. Using the terms you learned in this unit, we
might describe them as obligate anaerobes, alkaliphiles, mesophiles, etc. There are microbes
1|Page
,that call your skin home. Use at least 3-4 terms from this unit to describe skin microbes and
explain why you selected each term.
What do we call bacteria that grow at those temperatures?
Human skin is very salty (from sweat) so skin microbes could be called halophiles.
The skin is exposed to oxygen in our atmosphere so skin microbes could be obligate aerobes,
facultative anaerobes, or possibly aerotolerant anaerobes.
The skin is slightly acidic (from oil or sebum) so skin microbes could be acidophiles.
The skin is body temperature (37 degrees Celsius) or slightly below so skin microbes could be
mesophiles.
Skin microbes live in close association with humans so they could be called symbiotic.
Skin microbes are considered part of our normal microbiota that benefit us by preventing
transient pathogen colonization while we provide them with shelter and food so they could be
considered mutualistic.
In what phase of microbial growth are cells doubling at the fastest rate?
Log
In what phase of cell growth is the rate of growth or doubling of cells equal to the rate of death
of cell?
Stationary
In this stage of microbial growth, when transfered from one medium to another, we don't see
an increase in numbers. Rather we know that the microorganisms are metabolically active and
getting used to the environment.
Lag
2|Page
,In this stage of microbial growth, waste products of metabolism have built up and nutrients
have been depleted leading to rapid death of the cells.
Death
This class of bacteria thrive in very cold temperatures.
Psychrophiles
These bacteria require hydrostatic pressure to keep their enzymes in the correct conformation
for reactivity.
Barophiles
The bacteria in your stomach are likely these types of bacteria.
Acidophiles
Halophiles are likely to be found in fresh water lakes.
False
Bacterial growth is defined by an increase in cell
number
The molecule passes from one side of the membrane with no assistance via protein or ATP. It is
naturally traveling from an area of high concentration to low concentration
Diffusion
Water passes through the membrane from an area of high water concentration (low solute
concentration) to an area of low water concentration (high solute concentration.)
Osmosis
A molecule passes through a membrane with the help of a carrier protein. No ATP is involved
and it travels from an area of high concentration to low concentration, but the molecule is too
large, bulky, polar, or charged and cannot pass through the phospholipid portion of the
membrane.
Facilitated diffusion
Special solute binding proteins pick up the molecule and bring them to a tranporter protein
located in the membrane. ATP is used to pump the molecule through the transporter protein.
Carrier Mediated
3|Page
, A molecule is captured by a protein carrier and modified as it passes through the membrane.
Group Translocation
The entire membrane makes a pocket and eventual vesicle and any molecules that are bound to
the surface are brought inside the cell.
Endocytosis
You set up two cultures with an equal amounts of Escherichia coli. You label one culture "A" and
the other "B." Each culture is given 100mL of tryptic soy nutrient broth. You then take culture A
and incubate it in the absence of oxygen and take culture B and incubate it in the presence of
oxygen for one week. If E. coli is able to use both aerobic and anaerobic metabolism, the how
would we classify it? Is it an obligate aerobe, obligate anaerobe, or a facultative anaerobe?
Based on that information, which flask, A or B, would have more cells at the end of the week?
Fully explain your answer.
If they have the same amount of nutrients, the flask with oxygen will use them more efficiently
and produce more ATP which will allow more growth.
E. coli would be classified as a facultative anaerobe because it is capable of both aerobic and
anaerobic metabolic pathways.
Both cultures would grow. Culture A in the absence of oxygen would produce only 2ATP per
glucose. Culture B in the presence of oxygen would produce 38ATP per glucose. ATP is used by
to cell to do "cell work" which would include anabolic or building reactions like making new cell
components for binary fission and cell growth to occur. So the more ATP available, the more
growth. Both cultures started with the same amount of TSB and so the same amount of glucose.
The culture that was more efficient at extracting ATP (38 vs 2) per glucose molecule would be
the culture with the most growth.
Culture B would have more growth.
What is NAD (NAD+) and NADH? Describe them as if you were a chemist. Why is NAD needed
by all cells no matter what type of metabolism they use?
NAD or nicotinamide adenine dinulecotide, is a coenzyme, which is a substance that is needed
for all the enzymes that are in the body. It is used to start the Electron Transport Chain.
NADH or ninoctinamide adenine dinulecotide plus hydrogen, is a coenzyme and helps in the
chemical process that generates energy to the body.
4|Page
