MCB3023 Final Exam Questions with
Guaranteed Pass Solutions 2026
Updated.
When the diet of a ruminant is drastically changed from grass to a starch rich diet, the ruminant
may become very ill or die because - Answer of the production of large amounts of acid,
resulting in acidosis
Lichens contain - Answer at least one fungal heterotrophic partner and at least one
phototrophic partner
The bacterial group that is responsible for root nodule formation in legumes is - Answer
Rhizobia
Humans have a - Answer colonic fermentation
Leghemoglobin produced by plants is important for - Answer oxygen supply
Which of these contains zooxanthellae as photosynthetic symbionts? - Answer corals
How do termites obtain nitrogen in their diet? - Answer From nitrogen fixing bacteria in their
gut.
These genes are important for root nodule formation - Answer nod
The majority of Archaea found in the human intestinal tract are - Answer methanogens
What is an endophyte? - Answer a symbiont that lives inside plant cells
What is the human microbiome composed of? - Answer all microbes that live on or within
the human body
What are Zooxanthellae? - Answer photosynthetic symbionts of corals
Most primary endosymbionts of insects have all these in common, EXCEPT - Answer nitrogen
fixation genes
,An example of a rumen fermenter is the - Answer sheep
Many of the rumen bacteria specialize in the breakdown of these macromolecules - Answer
cellulose polymers
Which genes are encoding for subunits of nitrogenase, the main enzyme for nitrogen fixation? -
Answer nif genes
What is the e- donor for bacterial symbionts of tubeworms at hydrothermal vents? - Answer
H2S
Which of these is characteristic of the enzyme nitrogenase? - Answer it is irreversibly
inactivated by oxygen
Camels have a - Answer rumen fermentation
Herbivores mostly require microorganisms to help them with the digestion of this compound -
Answer cellulose
Which of these is true of a mutualistic relationship? - Answer both organisms benefit
How does vertical transmission of a pathogen occur? - Answer From mother to offspring
The Ebola virus is transmitted by a ____ mechanism - Answer zoonotic
This is an example of a virus known to undergo evolutionary change by reassortment of genetic
elements: - Answer influenza virus
Antibodies are: - Answer produced by B cells
Some T cells (T lymphocytes): - Answer induce necrosis of cells
In the CRISPR-Cas System, which component is responsible for phage destruction? - Answer
cRNA subunits
Which is an example of innate immunity? - Answer The removal of a bacterial cell in the
lungs by a resident macrophage
, Which cells are destroyed by hemolysins? - Answer red blood cells
LPS in Gram-negative contain - Answer an O-antigen
Which one of the following statements is NOT one of Koch's postulates? - Answer identify
and characterize endotoxins from the isolated microbe
Which is studied in the field of epidemiology? - Answer the spread patterns of all diseases
Name the type of viral infection in which the viral genome is present in infected cells but the
virus only replicates sporadically - Answer latent
Which of these could be accomplished with an ELISA? - Answer detection of specific
antibodies in serum
Pathogenicity islands are blocks of genes on the bacterial chromosomes that most likely arose
from this process - Answer horizontal gene transfer
The emergence of HIV/AIDS disease was most likely a result of: - Answer a rare zoonotic
transfer of a retrovirus strain to humans
Pathogenic E. coli strain O157:H7 evolved from a non=pathogenic strain as a result of this
genetic change - Answer the acquisition of virulence genes via horizontal gene transfer
The term describing a clustering of virulence genes on the chromosome of a pathogenic
microbe is: - Answer pathogenicity island
Which of these results in immunological memory? - Answer the adaptive immune response
Which one of the following is NOT a nonspecific natural defense barrier against microbial
invasion? - Answer antibodies produced from B lymphocytes
What is the primary effect of microbial lipopolysaccharides (LPS) on the host? - Answer
Triggers an intense inflammatory response
Botulinum toxin belongs to a group of toxins called A-B toxins. What does the term "A-B" refer
to? - Answer Their enzymatically active subunit and their cell-binding subunit.
Guaranteed Pass Solutions 2026
Updated.
When the diet of a ruminant is drastically changed from grass to a starch rich diet, the ruminant
may become very ill or die because - Answer of the production of large amounts of acid,
resulting in acidosis
Lichens contain - Answer at least one fungal heterotrophic partner and at least one
phototrophic partner
The bacterial group that is responsible for root nodule formation in legumes is - Answer
Rhizobia
Humans have a - Answer colonic fermentation
Leghemoglobin produced by plants is important for - Answer oxygen supply
Which of these contains zooxanthellae as photosynthetic symbionts? - Answer corals
How do termites obtain nitrogen in their diet? - Answer From nitrogen fixing bacteria in their
gut.
These genes are important for root nodule formation - Answer nod
The majority of Archaea found in the human intestinal tract are - Answer methanogens
What is an endophyte? - Answer a symbiont that lives inside plant cells
What is the human microbiome composed of? - Answer all microbes that live on or within
the human body
What are Zooxanthellae? - Answer photosynthetic symbionts of corals
Most primary endosymbionts of insects have all these in common, EXCEPT - Answer nitrogen
fixation genes
,An example of a rumen fermenter is the - Answer sheep
Many of the rumen bacteria specialize in the breakdown of these macromolecules - Answer
cellulose polymers
Which genes are encoding for subunits of nitrogenase, the main enzyme for nitrogen fixation? -
Answer nif genes
What is the e- donor for bacterial symbionts of tubeworms at hydrothermal vents? - Answer
H2S
Which of these is characteristic of the enzyme nitrogenase? - Answer it is irreversibly
inactivated by oxygen
Camels have a - Answer rumen fermentation
Herbivores mostly require microorganisms to help them with the digestion of this compound -
Answer cellulose
Which of these is true of a mutualistic relationship? - Answer both organisms benefit
How does vertical transmission of a pathogen occur? - Answer From mother to offspring
The Ebola virus is transmitted by a ____ mechanism - Answer zoonotic
This is an example of a virus known to undergo evolutionary change by reassortment of genetic
elements: - Answer influenza virus
Antibodies are: - Answer produced by B cells
Some T cells (T lymphocytes): - Answer induce necrosis of cells
In the CRISPR-Cas System, which component is responsible for phage destruction? - Answer
cRNA subunits
Which is an example of innate immunity? - Answer The removal of a bacterial cell in the
lungs by a resident macrophage
, Which cells are destroyed by hemolysins? - Answer red blood cells
LPS in Gram-negative contain - Answer an O-antigen
Which one of the following statements is NOT one of Koch's postulates? - Answer identify
and characterize endotoxins from the isolated microbe
Which is studied in the field of epidemiology? - Answer the spread patterns of all diseases
Name the type of viral infection in which the viral genome is present in infected cells but the
virus only replicates sporadically - Answer latent
Which of these could be accomplished with an ELISA? - Answer detection of specific
antibodies in serum
Pathogenicity islands are blocks of genes on the bacterial chromosomes that most likely arose
from this process - Answer horizontal gene transfer
The emergence of HIV/AIDS disease was most likely a result of: - Answer a rare zoonotic
transfer of a retrovirus strain to humans
Pathogenic E. coli strain O157:H7 evolved from a non=pathogenic strain as a result of this
genetic change - Answer the acquisition of virulence genes via horizontal gene transfer
The term describing a clustering of virulence genes on the chromosome of a pathogenic
microbe is: - Answer pathogenicity island
Which of these results in immunological memory? - Answer the adaptive immune response
Which one of the following is NOT a nonspecific natural defense barrier against microbial
invasion? - Answer antibodies produced from B lymphocytes
What is the primary effect of microbial lipopolysaccharides (LPS) on the host? - Answer
Triggers an intense inflammatory response
Botulinum toxin belongs to a group of toxins called A-B toxins. What does the term "A-B" refer
to? - Answer Their enzymatically active subunit and their cell-binding subunit.
