PLANT PATHOLOGY - FINAL EXAM
1. Rhizobium generating nodules in the roots of legumes; allows rhizobium to
live and helps legumes by fixing nitrogen
Which of the following is an example of mutualism
Answer Fusarium causing vascular wilt, dodder plant growing with tomatoes, Rhizobium generating nodules in
the roots of legumes.
Why?
2. rods and spirilla
Answer What are the common shapes of plant pathogenic bacteria?
3. +ssRNA group which is a single strand RNA that is immediately ready for
translation. The basis is the replication strategy of +ssRNA to -ssRNA to mRNA
then translated to proteins
Answer In the Baltimore classification system, most plant viruses fall into which group? What is the basis of this
classification?
4. preventing the introduction of pathogens in a new place
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30
,Answer What does exclusion refer to in disease management?
5. Erwinia tracheiphila
Answer What is the name of the pathogen that causes Cucumber bacterial wilt?
6. Pectobacterium carotovora
Answer What is the name of the pathogen that causes Soft rot of vegetables?
7. For a disease to occur pathogens needs to be abundant and virulent, environ-
ment in favorable conditions, and host is susceptible. A change in one of these
components can make it so conditions do not allow for infection. An exmaple
is not enough water for bacteria movement
Answer Explain the disease triangle. Illustrate how changes in one component can determine whether a
disease develops.
8. binary fission
Answer What is the main mode of bacterial reproduction in plants?
9. false
Answer True or false
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30
, All viruses contain both DNA and RNA
10. primary is initial causer of disease and secondary is the spread in the same
season
Answer How do you distinguish between primary and secondary inoculum?
11. biotroph; necrotroph
Answer A hemibiotroph starts as a but later switches to
12. By observing the cause, progression, signs, and spread. Abiotic disease is
over a large area of land while biotic can affect a single plant. Signs like fungal
mycelium and bacterial streaming can give visual clues for biotic and testing
like soil tests can help determine if abiotic
Answer How do you distinguish between a biotic disease and an abiotic disease? Explain.
13. gram staining. Relies on the gram positive bacteria having thick peptidogly-
can layers in cell wall and gram negative bacteria having thin peptidoglycan
3/
30
1. Rhizobium generating nodules in the roots of legumes; allows rhizobium to
live and helps legumes by fixing nitrogen
Which of the following is an example of mutualism
Answer Fusarium causing vascular wilt, dodder plant growing with tomatoes, Rhizobium generating nodules in
the roots of legumes.
Why?
2. rods and spirilla
Answer What are the common shapes of plant pathogenic bacteria?
3. +ssRNA group which is a single strand RNA that is immediately ready for
translation. The basis is the replication strategy of +ssRNA to -ssRNA to mRNA
then translated to proteins
Answer In the Baltimore classification system, most plant viruses fall into which group? What is the basis of this
classification?
4. preventing the introduction of pathogens in a new place
1/
30
,Answer What does exclusion refer to in disease management?
5. Erwinia tracheiphila
Answer What is the name of the pathogen that causes Cucumber bacterial wilt?
6. Pectobacterium carotovora
Answer What is the name of the pathogen that causes Soft rot of vegetables?
7. For a disease to occur pathogens needs to be abundant and virulent, environ-
ment in favorable conditions, and host is susceptible. A change in one of these
components can make it so conditions do not allow for infection. An exmaple
is not enough water for bacteria movement
Answer Explain the disease triangle. Illustrate how changes in one component can determine whether a
disease develops.
8. binary fission
Answer What is the main mode of bacterial reproduction in plants?
9. false
Answer True or false
2/
30
, All viruses contain both DNA and RNA
10. primary is initial causer of disease and secondary is the spread in the same
season
Answer How do you distinguish between primary and secondary inoculum?
11. biotroph; necrotroph
Answer A hemibiotroph starts as a but later switches to
12. By observing the cause, progression, signs, and spread. Abiotic disease is
over a large area of land while biotic can affect a single plant. Signs like fungal
mycelium and bacterial streaming can give visual clues for biotic and testing
like soil tests can help determine if abiotic
Answer How do you distinguish between a biotic disease and an abiotic disease? Explain.
13. gram staining. Relies on the gram positive bacteria having thick peptidogly-
can layers in cell wall and gram negative bacteria having thin peptidoglycan
3/
30
