EXAM 3 MICROBIOLOGY EXPECTED QUESTIONS WITH
VERIFIED ANSWERS
Question 1.
Which of the following organisms are most closely related? Are any two the same species? On what did
you base your answer?
ANSWER
A and D appear to be most closely related because they have similar GC moles %. No two are
the same species.
Question 2.
Difference between biological and mechanical transmission
ANSWER
biological transmission: pathogen multiplies in the vector
mechanical transmission: pathogens transmitted through physical contact
Question 3.
Which of these organisms are most closely related? Compare this answer with your response to review
question 1.
ANSWER
A and D are most closely related.
,Question 4.
Regarding the Order Rhizobiales of the Class alphaproteobacteria, which genus includes human
pathogens?
a. Brucella
b. Wolbachia
c. Agrobacterium
d. Bradyrhizobium
ANSWER
a. Brucella
Question 5.
analyze a DNA fingerprint result
ANSWER
lanes 1 and 6 are identical
lanes 2 and 3 are identical
lanes 4 and 5 are identical
Question 6.
6. Describe the use of a DNA probe and PCR for: b. Determining which of a group of bacterium are
most closely related.
ANSWER
DNA Probe - allows us to match enzymes from sample to determine molecular %
PCR - allows for replication and isolation of one strand of DNA to match to DNA probe
,Question 7.
The life cycle of the fish tapeworm Diphyllobothrium is similar to that of Taenia saginata, except that
the intermediate host is fish. Describe the life cycle and method of transmission to humans. Why are
freshwater fish more likely to be a source of tapeworm infection than marine fish?
ANSWER
Immature eggs-->oncosphere-->coracidia-->proceroid larvae (crustacean, first immediate host)-
->pleroceroid larvae (sparganum) (infective agent for humans) (freshwater fish, secondary
immediate host)-->predator fish ingests freshwater fish-->human ingests undercooked
predator fish-->immature adult tapeworms-->mature adult tapeworms-->immature eggs
released by the proglottids Freshwater fish are more likely to be a source of tapeworm
infection because tapeworms better survive in a freshwater environment than a saltwater
environment.
Question 8.
Why must transcription of a ss R N A; − (antisense) strand occur during multiplication?
ANSWER
Viral RNA is transcribed to a + strand to serve as
mRNA for protein synthesis
Question 9.
Viruses that utilize reverse transcriptase belong to the virus families
a. Herpesviridae and Retroviridae.
b. Herpesviridae and Poxviridae.
c. Retroviridae and Picornaviridae.
d. Rhabdoviridae and Herpesviridae.
e. Hepadnaviridae and Retroviridae.
ANSWER
e. Hepadnaviridae and Retroviridae.
, Question 10.
Compare specialized vs generalized transduction
ANSWER
specialized transduction:
- specific bacterial genes transferred to another bacterium via a phage
- changes genetic properties of the bacteria
- mediated by lysogenic phage
generalized transduction:
- bacterial genes picked up in a phage coat and transferred to another bacterium
- Any bacterial genes can be transferred
Question 11.
Into which group would you place a photosynthetic organism that lacks a nucleus and has a thin
peptidoglycan wall surrounded by an outer membrane?
a. Animalia
b. Fungi
c. Plantae
d. Firmicutes (gram-positive bacteria)
e. Proteobacteria (gram-negative bacteria)
ANSWER
e. Proteobacteria (gram-negative bacteria)
Question 12.
By what means are helminthic parasites transmitted to humans?
ANSWER
Ingestion
Question 13.
Spirillum is not classified as a spirochete because spirochetes
a. do not cause disease.
b. possess axial filaments.
c. possess flagella.
d. are prokaryotes.
e. none of the above
ANSWER
b. possess axial filaments.
VERIFIED ANSWERS
Question 1.
Which of the following organisms are most closely related? Are any two the same species? On what did
you base your answer?
ANSWER
A and D appear to be most closely related because they have similar GC moles %. No two are
the same species.
Question 2.
Difference between biological and mechanical transmission
ANSWER
biological transmission: pathogen multiplies in the vector
mechanical transmission: pathogens transmitted through physical contact
Question 3.
Which of these organisms are most closely related? Compare this answer with your response to review
question 1.
ANSWER
A and D are most closely related.
,Question 4.
Regarding the Order Rhizobiales of the Class alphaproteobacteria, which genus includes human
pathogens?
a. Brucella
b. Wolbachia
c. Agrobacterium
d. Bradyrhizobium
ANSWER
a. Brucella
Question 5.
analyze a DNA fingerprint result
ANSWER
lanes 1 and 6 are identical
lanes 2 and 3 are identical
lanes 4 and 5 are identical
Question 6.
6. Describe the use of a DNA probe and PCR for: b. Determining which of a group of bacterium are
most closely related.
ANSWER
DNA Probe - allows us to match enzymes from sample to determine molecular %
PCR - allows for replication and isolation of one strand of DNA to match to DNA probe
,Question 7.
The life cycle of the fish tapeworm Diphyllobothrium is similar to that of Taenia saginata, except that
the intermediate host is fish. Describe the life cycle and method of transmission to humans. Why are
freshwater fish more likely to be a source of tapeworm infection than marine fish?
ANSWER
Immature eggs-->oncosphere-->coracidia-->proceroid larvae (crustacean, first immediate host)-
->pleroceroid larvae (sparganum) (infective agent for humans) (freshwater fish, secondary
immediate host)-->predator fish ingests freshwater fish-->human ingests undercooked
predator fish-->immature adult tapeworms-->mature adult tapeworms-->immature eggs
released by the proglottids Freshwater fish are more likely to be a source of tapeworm
infection because tapeworms better survive in a freshwater environment than a saltwater
environment.
Question 8.
Why must transcription of a ss R N A; − (antisense) strand occur during multiplication?
ANSWER
Viral RNA is transcribed to a + strand to serve as
mRNA for protein synthesis
Question 9.
Viruses that utilize reverse transcriptase belong to the virus families
a. Herpesviridae and Retroviridae.
b. Herpesviridae and Poxviridae.
c. Retroviridae and Picornaviridae.
d. Rhabdoviridae and Herpesviridae.
e. Hepadnaviridae and Retroviridae.
ANSWER
e. Hepadnaviridae and Retroviridae.
, Question 10.
Compare specialized vs generalized transduction
ANSWER
specialized transduction:
- specific bacterial genes transferred to another bacterium via a phage
- changes genetic properties of the bacteria
- mediated by lysogenic phage
generalized transduction:
- bacterial genes picked up in a phage coat and transferred to another bacterium
- Any bacterial genes can be transferred
Question 11.
Into which group would you place a photosynthetic organism that lacks a nucleus and has a thin
peptidoglycan wall surrounded by an outer membrane?
a. Animalia
b. Fungi
c. Plantae
d. Firmicutes (gram-positive bacteria)
e. Proteobacteria (gram-negative bacteria)
ANSWER
e. Proteobacteria (gram-negative bacteria)
Question 12.
By what means are helminthic parasites transmitted to humans?
ANSWER
Ingestion
Question 13.
Spirillum is not classified as a spirochete because spirochetes
a. do not cause disease.
b. possess axial filaments.
c. possess flagella.
d. are prokaryotes.
e. none of the above
ANSWER
b. possess axial filaments.
