D311 Microbiology Final Examination
and Already Passed Answers 2025-
2026 Edition.
Which statement describes prokaryotic cells?
a) Prokaryotic cells are found in coccus form in both pairs and clusters.
b) Prokaryotic cells have multiple rod-shaped chromosomes.
c) Prokaryotic cells are found in chains of rods but not single rods.
d) Prokaryotic cells have a nucleus surrounded by a complex nuclear membrane. - Answer A
This is correct because prokaryotic cells can form cocus in both pairs and clusters
Which statement describes eukaryotic cells?
a) The exoskeletons of eukaryotic cells maintain and support the cells' shapes.
b) The nuclei of eukaryotic cells are surrounded by complex nuclear membranes.
c) The genomes of eukaryotic cells are usually packaged in single circular chromosomes.
d) The organelles of eukaryotic cells are held in place by semipermeable exoskeletons. - Answer
B
Which statement describes eukaryotic flagella?
a) Eukaryotic flagella can cover the entire surface of a cell.
b) Eukaryotic flagella are rotating structures.
c) Eukaryotic flagella have twelve pairs of microtubules.
d) Eukaryotic flagella are flexible, whip-like structures. - Answer D
Which statement describes the endomembrane system?
a) It is attached to the smooth endoplasmic reticulum and makes proteins for insertion into the
cell membrane.
b) It includes the Golgi apparatus, lysosomes, and vesicles.
c) It is a system that uses diffusion to transport materials inside of the cell.
d) It lacks membrane-bound organelles. - Answer B
,c) Both are made of long filaments that form visible colonies.
d) Both move with help from cilia and flagella. - Answer B
Why are algae considered photosynthetic organisms?
a) Algae cell walls are constructed with a material called peptidoglycan.
b) Algae contain substances that can be converted into biofuels.
c) Algae produce chemical energy from the sun's light energy.
d) Algae create waste products that other organisms can use to make energy. - Answer C
Why are plasmids important to the survival of organisms?
a) Plasmids exclusively contain the genes responsible for cellular replication in bacteria.
b) Plasmids can store excess nutrients in the cytoplasm of the cell.
c) Plasmids protect the bacterial genome in a dormant state during unfavorable environmental
conditions.
d) Plasmids carry genetic material, apart from the genome, that can benefit the organism. -
Answer D
Plasmids often carry genes that can offer beneficial traits such as antibiotic resistance
Which statement describes bacteria?
a) Some bacteria are eukaryotes.
b) Some bacteria have cell walls composed of mycolic acid.
c) Some bacteria are motile by cilia.
d) Some bacteria have cell walls composed of chitin. - Answer B
Mycolic acid can be found in the cell walls of acid-fast bacteria
Why are prokaryotes vital to life? - Answer Prokaryotes are vital to life because they are able
to recycle elements like carbon and nutrients. Organisms like animals need organic carbon in
order to grow but, unlike prokaryotes, they are unable to use inorganic carbon sources like CO2.
The enzyme nitrogenase is only found in prokaryotes
Which aspect of nutrient cycling is performed only by prokaryotes?
,d) Nitrogen fixation - Answer D
The enzyme nitrogenase is only found in prokaryotes; it is vital to life and the process of
nitrogen fixation
How does microbial bioremediation benefit the environment?
a) By helping to minimize the growth of pathogens in different parts of the body
b) By helping to metabolize and remove pollutants in the atmosphere
c) By producing complex organic pharmaceutical compounds used in antibiotics, vaccines, and
vitamins
d) By producing gases, such as carbon dioxide, which are used to make biofuels - Answer B
This is the correct answer because the definition of bioremediation is the process of bacteria
using a toxic structure to grow which leads to it being removed from the environment. Occurs
often by breaking it down into its nontoxic components
What describes the relationship of pathogens to virulence?
a) Highly virulent pathogens almost always lead to a disease state when introduced to the body.
b) Pathogens that cause an infection cannot also be virulent.
c) Highly virulent pathogens are highly susceptible to the human immune system.
d) Less virulent pathogens are less likely to lead to an infection. - Answer A
What is the key difference between a primary pathogen and an opportunistic pathogen?
a) Primary pathogens can be fought off by the body's immune defense system, whereas
opportunistic pathogens require synthetic interventions.
b) Primary pathogens can infect certain people, whereas opportunistic pathogens can infect
anyone.
c) Primary pathogens can infect anyone, whereas opportunistic pathogens can cause disease if
the host is immunocompromised.
d) Primary pathogens are part of the human microbiome, whereas opportunistic pathogens are
transmitted from another host. - Answer C
How can disease expression be described?
a) Pathogens with high virulence tend to cause symptoms that include low-grade fevers or
, d) Signs and symptoms associated with illness can be a result of many things, including an
immune response - Answer D
What is the correct understanding of the median infectious dose?
a) It is the number of pathogenic cells required to kill 50% of infected animals.
b) It is the number of pathogenic cells required to cause active infection in 50% of inoculated
animals.
c) It is the amount of toxin required to see an immune response to infection in 50% of people.
d) It is the amount of toxin required to infect 50% of the human population. - Answer B
Which structure aids in the evasion of phagocytosis by preventing immune cells from adhering
to pathogens?
a) Pili
b) Fimbriae
c) Peptidoglycan
d) Capsule - Answer D
Which group contains a pathogen that adheres to host cells by using a large adhesive disc?
a) Viruses
b) Protozoans
c) Fungi
d) Bacteria - Answer B
Which phenomenon is found only in viruses?
a) Antigenic drift
b) Antigenic shift
c) Mycotoxin production
d) Capsule formation - Answer B
This is a major change of surface antigens that can occur when multiple viruses invade a single
cell causing their genomes to mix and resort
and Already Passed Answers 2025-
2026 Edition.
Which statement describes prokaryotic cells?
a) Prokaryotic cells are found in coccus form in both pairs and clusters.
b) Prokaryotic cells have multiple rod-shaped chromosomes.
c) Prokaryotic cells are found in chains of rods but not single rods.
d) Prokaryotic cells have a nucleus surrounded by a complex nuclear membrane. - Answer A
This is correct because prokaryotic cells can form cocus in both pairs and clusters
Which statement describes eukaryotic cells?
a) The exoskeletons of eukaryotic cells maintain and support the cells' shapes.
b) The nuclei of eukaryotic cells are surrounded by complex nuclear membranes.
c) The genomes of eukaryotic cells are usually packaged in single circular chromosomes.
d) The organelles of eukaryotic cells are held in place by semipermeable exoskeletons. - Answer
B
Which statement describes eukaryotic flagella?
a) Eukaryotic flagella can cover the entire surface of a cell.
b) Eukaryotic flagella are rotating structures.
c) Eukaryotic flagella have twelve pairs of microtubules.
d) Eukaryotic flagella are flexible, whip-like structures. - Answer D
Which statement describes the endomembrane system?
a) It is attached to the smooth endoplasmic reticulum and makes proteins for insertion into the
cell membrane.
b) It includes the Golgi apparatus, lysosomes, and vesicles.
c) It is a system that uses diffusion to transport materials inside of the cell.
d) It lacks membrane-bound organelles. - Answer B
,c) Both are made of long filaments that form visible colonies.
d) Both move with help from cilia and flagella. - Answer B
Why are algae considered photosynthetic organisms?
a) Algae cell walls are constructed with a material called peptidoglycan.
b) Algae contain substances that can be converted into biofuels.
c) Algae produce chemical energy from the sun's light energy.
d) Algae create waste products that other organisms can use to make energy. - Answer C
Why are plasmids important to the survival of organisms?
a) Plasmids exclusively contain the genes responsible for cellular replication in bacteria.
b) Plasmids can store excess nutrients in the cytoplasm of the cell.
c) Plasmids protect the bacterial genome in a dormant state during unfavorable environmental
conditions.
d) Plasmids carry genetic material, apart from the genome, that can benefit the organism. -
Answer D
Plasmids often carry genes that can offer beneficial traits such as antibiotic resistance
Which statement describes bacteria?
a) Some bacteria are eukaryotes.
b) Some bacteria have cell walls composed of mycolic acid.
c) Some bacteria are motile by cilia.
d) Some bacteria have cell walls composed of chitin. - Answer B
Mycolic acid can be found in the cell walls of acid-fast bacteria
Why are prokaryotes vital to life? - Answer Prokaryotes are vital to life because they are able
to recycle elements like carbon and nutrients. Organisms like animals need organic carbon in
order to grow but, unlike prokaryotes, they are unable to use inorganic carbon sources like CO2.
The enzyme nitrogenase is only found in prokaryotes
Which aspect of nutrient cycling is performed only by prokaryotes?
,d) Nitrogen fixation - Answer D
The enzyme nitrogenase is only found in prokaryotes; it is vital to life and the process of
nitrogen fixation
How does microbial bioremediation benefit the environment?
a) By helping to minimize the growth of pathogens in different parts of the body
b) By helping to metabolize and remove pollutants in the atmosphere
c) By producing complex organic pharmaceutical compounds used in antibiotics, vaccines, and
vitamins
d) By producing gases, such as carbon dioxide, which are used to make biofuels - Answer B
This is the correct answer because the definition of bioremediation is the process of bacteria
using a toxic structure to grow which leads to it being removed from the environment. Occurs
often by breaking it down into its nontoxic components
What describes the relationship of pathogens to virulence?
a) Highly virulent pathogens almost always lead to a disease state when introduced to the body.
b) Pathogens that cause an infection cannot also be virulent.
c) Highly virulent pathogens are highly susceptible to the human immune system.
d) Less virulent pathogens are less likely to lead to an infection. - Answer A
What is the key difference between a primary pathogen and an opportunistic pathogen?
a) Primary pathogens can be fought off by the body's immune defense system, whereas
opportunistic pathogens require synthetic interventions.
b) Primary pathogens can infect certain people, whereas opportunistic pathogens can infect
anyone.
c) Primary pathogens can infect anyone, whereas opportunistic pathogens can cause disease if
the host is immunocompromised.
d) Primary pathogens are part of the human microbiome, whereas opportunistic pathogens are
transmitted from another host. - Answer C
How can disease expression be described?
a) Pathogens with high virulence tend to cause symptoms that include low-grade fevers or
, d) Signs and symptoms associated with illness can be a result of many things, including an
immune response - Answer D
What is the correct understanding of the median infectious dose?
a) It is the number of pathogenic cells required to kill 50% of infected animals.
b) It is the number of pathogenic cells required to cause active infection in 50% of inoculated
animals.
c) It is the amount of toxin required to see an immune response to infection in 50% of people.
d) It is the amount of toxin required to infect 50% of the human population. - Answer B
Which structure aids in the evasion of phagocytosis by preventing immune cells from adhering
to pathogens?
a) Pili
b) Fimbriae
c) Peptidoglycan
d) Capsule - Answer D
Which group contains a pathogen that adheres to host cells by using a large adhesive disc?
a) Viruses
b) Protozoans
c) Fungi
d) Bacteria - Answer B
Which phenomenon is found only in viruses?
a) Antigenic drift
b) Antigenic shift
c) Mycotoxin production
d) Capsule formation - Answer B
This is a major change of surface antigens that can occur when multiple viruses invade a single
cell causing their genomes to mix and resort
