STRAIGHTERLINE MICRO 250 FINAL EXAM PREP 2025 | REAL EXAM QUESTIONS
& VERIFIED ANSWERS | SCORED A+
Which class of eukaryotic microorganisms can be subdivided into groups such as
Mastigophora, Sarcodina, Ciliophora, and Apicomplexa?
A. Helminths
B. Algae
C. Protozoa
D. Fungi - (answers)Protozoa
Genetic material can be excised from one chromosome and directly integrated into
another via
A. conjugation.
B. transformation.
C. transduction.
D. transposons. - (answers)transposons.
Which immune cell secretes numerous cytokines that help to coordinate the response of
other immune cells?
A. B cell
B. TH cell
C. TC cell
D. Platelets - (answers)TH cell
Which of the following enzymes are used to amplify DNA during PCR?
A. restriction endonuclease
B. DNA polymerase
C. reverse transcriptase
D. DNA ligase - (answers)DNA polymerase
,In the nitrogen cycle, which of the following steps involves removal of nitrogen from the
atmosphere by bacteria? - (answers)nitrogen fixation, In nitrogen fixation, nitrogen is
removed from the atmosphere by nitrogen-fixing bacteria and converted to ammonia.
If enough h+ ions are added to pure water to raise the H+ concentration of the solution
to ten times higher than the original concentration, what is the resulting OH-
concentration of the solution? - (answers)10 -8M
Fungi are able to reproduce asexually by creating conidiospores and sporangiospores.
Which of the following is an accurate explanation for why it is advantageous that they
are also capable of sexual reproduction?
Select one:
a. Asexually produced offspring are more likely to compete for resources and will kill off
the parental fungi.
b. Fungi normally produce sexually but produce asexually in harsh conditions such as
severe drought.
c. Offspring from two parents may have variations in form and function that contribute to
survival of the species.
d. Sexual reproduction produces more offspring at a faster rate than spore formation. -
(answers)Offspring from two parents may have variations in form and function that
contribute to survival of the species.
In a laboratory bacterial cell culture that has been infected by a virus, plaques are areas
in which
Select one:
a. bacterial cells are resistant to the virus and have not been infected.
b. there is no nutrient available for the bacteria to grow.
c. the virus has spread and left behind the remains of dead cells.
d. the virus has not yet spread to that area of cells. - (answers)the virus has spread and
left behind the remains of dead cells.
The sun's energy is delivered as discrete packets that travel as waves and are called
Select one:
a. ATP.
b. carotenoids.
c. NADP.
d. photons. - (answers)photons.
Which of the following is a characteristic of aerobic respiration?
Select one:
a. Oxygen-containing ions act as the final electron acceptors in electron transport.
b. The process includes glycolysis, the Krebs cycle, and the electron transport chain.
c. Aerobic respiration produces a total of 2 ATP molecules.
d. Aerobic respiration produces lactic acid. - (answers)The three stages of aerobic
respiration are glycolysis, the Krebs cycle, and the electron transport chain.
,n completing protein synthesis in a prokaryote, what basic message is carried by a
specialized codon that has no corresponding tRNA?
Select one:
a. "Fold peptide chain."
b. "Terminate here."
c. "Add cofactor."
d. "Clip starting amino acid." - (answers)"Terminate here." The specialized codon
signals the end of protein synthesis; there is not RNA because it is only needed if the
process is to continue.
Microbial drug resistance can be caused by mutations or by introduction of new genes
into a population. Which of the following can only be caused by the introduction of new
genes into a population?
Select one:
a. a metabolic pathway in the bacterium is shut down
b. binding sites for the drug are reduced in number or affinity to the drug
c. new enzymes that inactivate the drug are synthesized
d. uptake of the drug into the bacterium is diminished - (answers)new enzymes that
inactivate the drug are synthesized. This can only occur if new genes are introduced
into the population.
Why do the hands, feet, and breasts have more lymphatic vessels for host defense than
other areas of the human body?
Select one:
a. They have a high risk for infection due to frequent contact.
b. They have a greater density of nerves.
c. They require complex movement of fluids from the extremities.
d. They are located a long distance from the thalamus. - (answers)They have a high risk
for infection due to frequent contact.
Penicillin functions as an antimicrobial agent by inhibiting bacterial
Select one:
a. cell wall synthesis.
b. folic acid synthesis.
c. protein synthesis.
d. RNA and DNA function. - (answers)cell wall synthesis. Penicillin belongs to a class of
antibacterial agents that interfere with the production of the material that makes up the
bacterial cell wall. The bacteria must constantly replace this material or they will become
susceptible to rupture due to osmotic pressure.
If enough ions are added to pure water to raise the concentration of the solution to ten
times higher than the original concentration, what is the resulting concentration of the
solution? - (answers)
, The study of evolutionary relationships among organisms is called -
(answers)phylogeny
The three cell types discussed, eukaryotes, archaea, and bacteria, all derived from -
(answers)Last Universal Common Ancestor
Organisms called parasites are - (answers)always harmful to their host.
Which of the following does not indicate microbe involvement in energy and nutrient
flow - (answers)Thermal hot springs warmed by heat from earth's interior
The subatomic particles that surround the nucleus are the - (answers)Electrons
The number one worldwide infectious diseases are - (answers)respiratory diseases
A fat is called _____ if all carbons of the fatty acid chain are single-bonded to 2 other
carbons and 2 hydrogens. - (answers)saturated
One technique for staining bacteria for viewing under the microscope is called the Gram
stain. In this technique, alcohol is used as a decolorizer because it degrades the outer
membrane found in some bacteria. What chemical component of the cell does alcohol
affect? - (answers)lipid
If a microbiologist is studying a specimen at a total magnification of 950X, what is the
magnifying power of the objective lens if the ocular lens is 10X? - (answers)95X
NASA has published a list of criteria for identifying fossil bacteria in samples from Mars,
as part of a search for evidence of life. Which of the following is good evidence for the
presence of bacterial cells? - (answers)cell size of 0.5 to 2 microns
Which type of microscope achieves the greatest resolution and highest magnification? -
(answers)electron
Which of the following is produced by adding 1% to 5% agar to nutrient broth that is
then boiled and cooled? - (answers)a solid medium
a spongiform encephalopathy of humans - (answers)Creutzfeldt-Jacob disease
The term that refers to flagella at both poles of the cell is ______. -
(answers)amphitrichous
In the condition called athlete's foot, the fungus Trichophyton consumes the keratin
protein found in hair, nails, and dead skin. Which of the following descriptors does not
apply to Trichophyton? - (answers)saprobe
& VERIFIED ANSWERS | SCORED A+
Which class of eukaryotic microorganisms can be subdivided into groups such as
Mastigophora, Sarcodina, Ciliophora, and Apicomplexa?
A. Helminths
B. Algae
C. Protozoa
D. Fungi - (answers)Protozoa
Genetic material can be excised from one chromosome and directly integrated into
another via
A. conjugation.
B. transformation.
C. transduction.
D. transposons. - (answers)transposons.
Which immune cell secretes numerous cytokines that help to coordinate the response of
other immune cells?
A. B cell
B. TH cell
C. TC cell
D. Platelets - (answers)TH cell
Which of the following enzymes are used to amplify DNA during PCR?
A. restriction endonuclease
B. DNA polymerase
C. reverse transcriptase
D. DNA ligase - (answers)DNA polymerase
,In the nitrogen cycle, which of the following steps involves removal of nitrogen from the
atmosphere by bacteria? - (answers)nitrogen fixation, In nitrogen fixation, nitrogen is
removed from the atmosphere by nitrogen-fixing bacteria and converted to ammonia.
If enough h+ ions are added to pure water to raise the H+ concentration of the solution
to ten times higher than the original concentration, what is the resulting OH-
concentration of the solution? - (answers)10 -8M
Fungi are able to reproduce asexually by creating conidiospores and sporangiospores.
Which of the following is an accurate explanation for why it is advantageous that they
are also capable of sexual reproduction?
Select one:
a. Asexually produced offspring are more likely to compete for resources and will kill off
the parental fungi.
b. Fungi normally produce sexually but produce asexually in harsh conditions such as
severe drought.
c. Offspring from two parents may have variations in form and function that contribute to
survival of the species.
d. Sexual reproduction produces more offspring at a faster rate than spore formation. -
(answers)Offspring from two parents may have variations in form and function that
contribute to survival of the species.
In a laboratory bacterial cell culture that has been infected by a virus, plaques are areas
in which
Select one:
a. bacterial cells are resistant to the virus and have not been infected.
b. there is no nutrient available for the bacteria to grow.
c. the virus has spread and left behind the remains of dead cells.
d. the virus has not yet spread to that area of cells. - (answers)the virus has spread and
left behind the remains of dead cells.
The sun's energy is delivered as discrete packets that travel as waves and are called
Select one:
a. ATP.
b. carotenoids.
c. NADP.
d. photons. - (answers)photons.
Which of the following is a characteristic of aerobic respiration?
Select one:
a. Oxygen-containing ions act as the final electron acceptors in electron transport.
b. The process includes glycolysis, the Krebs cycle, and the electron transport chain.
c. Aerobic respiration produces a total of 2 ATP molecules.
d. Aerobic respiration produces lactic acid. - (answers)The three stages of aerobic
respiration are glycolysis, the Krebs cycle, and the electron transport chain.
,n completing protein synthesis in a prokaryote, what basic message is carried by a
specialized codon that has no corresponding tRNA?
Select one:
a. "Fold peptide chain."
b. "Terminate here."
c. "Add cofactor."
d. "Clip starting amino acid." - (answers)"Terminate here." The specialized codon
signals the end of protein synthesis; there is not RNA because it is only needed if the
process is to continue.
Microbial drug resistance can be caused by mutations or by introduction of new genes
into a population. Which of the following can only be caused by the introduction of new
genes into a population?
Select one:
a. a metabolic pathway in the bacterium is shut down
b. binding sites for the drug are reduced in number or affinity to the drug
c. new enzymes that inactivate the drug are synthesized
d. uptake of the drug into the bacterium is diminished - (answers)new enzymes that
inactivate the drug are synthesized. This can only occur if new genes are introduced
into the population.
Why do the hands, feet, and breasts have more lymphatic vessels for host defense than
other areas of the human body?
Select one:
a. They have a high risk for infection due to frequent contact.
b. They have a greater density of nerves.
c. They require complex movement of fluids from the extremities.
d. They are located a long distance from the thalamus. - (answers)They have a high risk
for infection due to frequent contact.
Penicillin functions as an antimicrobial agent by inhibiting bacterial
Select one:
a. cell wall synthesis.
b. folic acid synthesis.
c. protein synthesis.
d. RNA and DNA function. - (answers)cell wall synthesis. Penicillin belongs to a class of
antibacterial agents that interfere with the production of the material that makes up the
bacterial cell wall. The bacteria must constantly replace this material or they will become
susceptible to rupture due to osmotic pressure.
If enough ions are added to pure water to raise the concentration of the solution to ten
times higher than the original concentration, what is the resulting concentration of the
solution? - (answers)
, The study of evolutionary relationships among organisms is called -
(answers)phylogeny
The three cell types discussed, eukaryotes, archaea, and bacteria, all derived from -
(answers)Last Universal Common Ancestor
Organisms called parasites are - (answers)always harmful to their host.
Which of the following does not indicate microbe involvement in energy and nutrient
flow - (answers)Thermal hot springs warmed by heat from earth's interior
The subatomic particles that surround the nucleus are the - (answers)Electrons
The number one worldwide infectious diseases are - (answers)respiratory diseases
A fat is called _____ if all carbons of the fatty acid chain are single-bonded to 2 other
carbons and 2 hydrogens. - (answers)saturated
One technique for staining bacteria for viewing under the microscope is called the Gram
stain. In this technique, alcohol is used as a decolorizer because it degrades the outer
membrane found in some bacteria. What chemical component of the cell does alcohol
affect? - (answers)lipid
If a microbiologist is studying a specimen at a total magnification of 950X, what is the
magnifying power of the objective lens if the ocular lens is 10X? - (answers)95X
NASA has published a list of criteria for identifying fossil bacteria in samples from Mars,
as part of a search for evidence of life. Which of the following is good evidence for the
presence of bacterial cells? - (answers)cell size of 0.5 to 2 microns
Which type of microscope achieves the greatest resolution and highest magnification? -
(answers)electron
Which of the following is produced by adding 1% to 5% agar to nutrient broth that is
then boiled and cooled? - (answers)a solid medium
a spongiform encephalopathy of humans - (answers)Creutzfeldt-Jacob disease
The term that refers to flagella at both poles of the cell is ______. -
(answers)amphitrichous
In the condition called athlete's foot, the fungus Trichophyton consumes the keratin
protein found in hair, nails, and dead skin. Which of the following descriptors does not
apply to Trichophyton? - (answers)saprobe
