1|Page
PCA PLANT PATHOGENS EXAM LATEST 2025/ 2026 |
COMPLETE QUESTIONS AND VERIFIED DETAILED
ANSWERS/ LATEST EXAM!!!
7. The nonliving components of an ecosystem are called:
A. Biotic compounds
B. Abiotic compounds
C. Mineral components
D. Environmental components - Answer-B. Abiotic
compounds
8. Which of the following ecological concepts is illustrated
in a food web?
A. Population equilibrium
B. mutualism
C. Biogeochemical cycles
D. Competition - Answer-B. mutualism
9. What is a limiting factor?
A. A biotic factor that stops the growth of a plant of animal
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B. A factor that is required for the growth and survival of an
organism
C. One of many soil nutrients that regulates the growth of
a plant
D. An action made by a consumer that limits the
population size of a species - Answer-B. A factor that is
required for the growth and survival of an organism
10. The mean population level around which a species'
characteristic abundance fluctuates is the species?
A. Density dependence
B. Equilibrium position
C. Population density
D. Abundance level - Answer-B. Equilibrium position
11. Many agricultural pest species such as foliar
pathogens, aphids, mites and small seeded weeds are
considered:
A. S strategists
B. K strategists
C. R strategists
D. C strategists - Answer-C. R strategists
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12. In general, how does the amount of biodiversity in an
agroecosystem compare to that of a natural, more mature
ecosystem? Biodiversity level is:
A. Equal among most ecosystems
B. Lower in an agroecosystem than a natural system
C. Higher in an agroecosystem than a natural system
D. Not measureable in agroecosystems - Answer-B. Lower
in an agroecosystem than a natural system
13. The goal of pest eradication is generally:
A. To eliminate newly invading pests
B. Aimed a eliminating exotic pests from a given county
C. To reduce existing pest populations
D. To discourage damaging pest populations form
occurring in a given area - Answer-A. To eliminate newly
invading pests
14. Secondary pests are pests that:
A. Damage crop plants but do not kill them
B. Become prevalent after control actions have been taken
to control key pests
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C. Damage the crop plant but do not damage the
harvested part
D. Harm crop plants but never cause enough damage to
be economically important - Answer-B. Become prevalent
after control actions have been taken to control key pests
15. What is the relationship between a treatment threshold
and an economic injury level?
A. A treatment threshold is always higher than the
economic injury level
B. An economic injury level is always higher than the
treatment threshold
C. Economic injury levels are equal to treatment
thresholds
D. Economic injury levels have been determined for all
classes of pests buy treatment thresholds have not. -
Answer-B. An economic injury level is always higher than
the treatment threshold
16. What is the "aesthetic injury level"?
A. The population level of a pest at which foliar damage
will occur
PCA PLANT PATHOGENS EXAM LATEST 2025/ 2026 |
COMPLETE QUESTIONS AND VERIFIED DETAILED
ANSWERS/ LATEST EXAM!!!
7. The nonliving components of an ecosystem are called:
A. Biotic compounds
B. Abiotic compounds
C. Mineral components
D. Environmental components - Answer-B. Abiotic
compounds
8. Which of the following ecological concepts is illustrated
in a food web?
A. Population equilibrium
B. mutualism
C. Biogeochemical cycles
D. Competition - Answer-B. mutualism
9. What is a limiting factor?
A. A biotic factor that stops the growth of a plant of animal
,2|Page
B. A factor that is required for the growth and survival of an
organism
C. One of many soil nutrients that regulates the growth of
a plant
D. An action made by a consumer that limits the
population size of a species - Answer-B. A factor that is
required for the growth and survival of an organism
10. The mean population level around which a species'
characteristic abundance fluctuates is the species?
A. Density dependence
B. Equilibrium position
C. Population density
D. Abundance level - Answer-B. Equilibrium position
11. Many agricultural pest species such as foliar
pathogens, aphids, mites and small seeded weeds are
considered:
A. S strategists
B. K strategists
C. R strategists
D. C strategists - Answer-C. R strategists
,3|Page
12. In general, how does the amount of biodiversity in an
agroecosystem compare to that of a natural, more mature
ecosystem? Biodiversity level is:
A. Equal among most ecosystems
B. Lower in an agroecosystem than a natural system
C. Higher in an agroecosystem than a natural system
D. Not measureable in agroecosystems - Answer-B. Lower
in an agroecosystem than a natural system
13. The goal of pest eradication is generally:
A. To eliminate newly invading pests
B. Aimed a eliminating exotic pests from a given county
C. To reduce existing pest populations
D. To discourage damaging pest populations form
occurring in a given area - Answer-A. To eliminate newly
invading pests
14. Secondary pests are pests that:
A. Damage crop plants but do not kill them
B. Become prevalent after control actions have been taken
to control key pests
, 4|Page
C. Damage the crop plant but do not damage the
harvested part
D. Harm crop plants but never cause enough damage to
be economically important - Answer-B. Become prevalent
after control actions have been taken to control key pests
15. What is the relationship between a treatment threshold
and an economic injury level?
A. A treatment threshold is always higher than the
economic injury level
B. An economic injury level is always higher than the
treatment threshold
C. Economic injury levels are equal to treatment
thresholds
D. Economic injury levels have been determined for all
classes of pests buy treatment thresholds have not. -
Answer-B. An economic injury level is always higher than
the treatment threshold
16. What is the "aesthetic injury level"?
A. The population level of a pest at which foliar damage
will occur
