MCB3023 Midterm 4 Test Questions
with Correct Revised Solutions 2025-
2026 Updated.
Camels have a:
A. cecal fermentation
B. stomach fermentation
C. colonic fermentation
D. rumen fermentation - Answer D
The emergence of HIV/AIDS disease was most likely a result of:
A. a mutation in an existing retrovirus that allowed for increased spread between humans.
B. an increase in virulence of an existing human retrovirus.
C. a rare zoonotic transfer of a retrovirus strain to humans.
D. a change in human behavior that allowed the virus to infect bats. - Answer C
An attachment structure which aids in overcoming the charge repulsion between host/microbe
cells is:
A. Fimbriae
B. peptidoglycan
C. cas9
D. conjugation nucleases - Answer A
What does a high case-to-infection ratio (CI) indicate
A. that most people infected by the pathogen will develop the disease
B. that the disease is usually very mild
C. that most people infected by the pathogen will not develop the disease
,A. triggers an intense inflammatory response
B. lyses epithelial cells
C. attacks cells of the immune system
D. acts as a neurotoxin - Answer A
What is the electron donor for bacterial symbionts of tubeworms at hydrothermal vents?
A. oxygen
B. H2S
C. ferric iron (Fe3+)
D. carbon dioxide - Answer B
Name the type of viral infection in which the viral genome is present in infected cells but the
virus only replicates sporadically
A. latent
B. acute
C. persistant
D. lytic - Answer A
These are cells of the innate immune system:
A. macrophages
B. B cells
C. MHC
D. T helper cells - Answer A
Which of these would lead to a recombination of genetic elements in viruses?
A. Errors during RNA replication.
B. Errors during DNA replication.
, A. the innate immune response
B. the adaptive immune response
C. passive immunity from mother to offspring
D. the non-specific immune response - Answer B
Which of these is characteristic of the enzyme nitrogenase?
A. It is irreversibly inactivated by oxygen.
B. It is found in all plant symbionts.
C. It converts dinitrogen to nitrate.
D. It is found in both prokaryotes and eukaryotes. - Answer A
Which of these contains zooxanthellae as photosynthetic symbionts?
A. corals
B. tubeworms
C. lichen
D. termites - Answer A
Lichens contain:
A. at least one fungal heterotrophic partner and at least one phototrophic partner
B. chemolithoautotrophs
C. root nodules
D. a heterotrophic partner and at least one fungal phototrophic partner - Answer A
How do termites obtain nitrogen in their diet?
A. From digestion of cellulose.
B. From digestion of wood.
with Correct Revised Solutions 2025-
2026 Updated.
Camels have a:
A. cecal fermentation
B. stomach fermentation
C. colonic fermentation
D. rumen fermentation - Answer D
The emergence of HIV/AIDS disease was most likely a result of:
A. a mutation in an existing retrovirus that allowed for increased spread between humans.
B. an increase in virulence of an existing human retrovirus.
C. a rare zoonotic transfer of a retrovirus strain to humans.
D. a change in human behavior that allowed the virus to infect bats. - Answer C
An attachment structure which aids in overcoming the charge repulsion between host/microbe
cells is:
A. Fimbriae
B. peptidoglycan
C. cas9
D. conjugation nucleases - Answer A
What does a high case-to-infection ratio (CI) indicate
A. that most people infected by the pathogen will develop the disease
B. that the disease is usually very mild
C. that most people infected by the pathogen will not develop the disease
,A. triggers an intense inflammatory response
B. lyses epithelial cells
C. attacks cells of the immune system
D. acts as a neurotoxin - Answer A
What is the electron donor for bacterial symbionts of tubeworms at hydrothermal vents?
A. oxygen
B. H2S
C. ferric iron (Fe3+)
D. carbon dioxide - Answer B
Name the type of viral infection in which the viral genome is present in infected cells but the
virus only replicates sporadically
A. latent
B. acute
C. persistant
D. lytic - Answer A
These are cells of the innate immune system:
A. macrophages
B. B cells
C. MHC
D. T helper cells - Answer A
Which of these would lead to a recombination of genetic elements in viruses?
A. Errors during RNA replication.
B. Errors during DNA replication.
, A. the innate immune response
B. the adaptive immune response
C. passive immunity from mother to offspring
D. the non-specific immune response - Answer B
Which of these is characteristic of the enzyme nitrogenase?
A. It is irreversibly inactivated by oxygen.
B. It is found in all plant symbionts.
C. It converts dinitrogen to nitrate.
D. It is found in both prokaryotes and eukaryotes. - Answer A
Which of these contains zooxanthellae as photosynthetic symbionts?
A. corals
B. tubeworms
C. lichen
D. termites - Answer A
Lichens contain:
A. at least one fungal heterotrophic partner and at least one phototrophic partner
B. chemolithoautotrophs
C. root nodules
D. a heterotrophic partner and at least one fungal phototrophic partner - Answer A
How do termites obtain nitrogen in their diet?
A. From digestion of cellulose.
B. From digestion of wood.
