PCA PLANT PATHOGENS Exam 2025 UPDATE/PRACTICE
QUESTIONS AND CORRECT VERIFIED ANSWERS(complete
solutions) ASSURED SUCCESS/GRADED A+!!!
Biotic factors of plant disease - CORRECT ANSWER-Living organisms (fungi,
bacteria, viruses)
Obligate parasite - CORRECT ANSWER-unable to grow outside of a living host
Facultative saprophyte - CORRECT ANSWER-prefers living organic matter as a
source of nutrition but can adapt to the use of dead organic matter under certain
conditions
Facultative parasite - CORRECT ANSWER-A pathogen that prefers dead
inorganic material, but can also obtain nourishment from living organic material
Biotroph - CORRECT ANSWER-Any parasite that cannot survive in a dead host
and therefore keeps it alive
Necrotroph - CORRECT ANSWER-Parasite that kills host cells
,Koch's Postulates - CORRECT ANSWER-series of guidelines used to identify the
microorganism that causes a specific disease
Plant Disease Definition - CORRECT ANSWER-Abnormal physiological processes
caused by a causal pathogen
Economic significance of plant diseases - CORRECT ANSWER-Losses of yield,
crops, inputs, land
Pathogen - CORRECT ANSWER-Causal agent of disease
Signs of disease - CORRECT ANSWER-Structures of the pathogen
Symptoms of disease - CORRECT ANSWER-Plant response to pathogen infection
Abiotic factors of plant disease - CORRECT ANSWER-Air pollution, temperature,
nutrients
Three components of disease triangle - CORRECT ANSWER-Causal agent,
environment, host
Role of each component of disease triangle - CORRECT ANSWER-All three must
be present for disease to occur. Environment must favor causal agent. Host must
favor causal agent.
,How humans impact each component of disease triangle - CORRECT ANSWER-
Manipulate the environment, host-plant resistance,
preventative/suppressive/erradicative pesticides
Impact of epidemic when one component of disease triangle does not come into
contact with the other two components - CORRECT ANSWER-Slows epidemic to
a halt. Disease spread needs all three components interacting
Management strategy to break environment component - CORRECT ANSWER-
Alter planting dates, remove alternative hosts, alter harvest
Management strategy to break host component - CORRECT ANSWER-Alternate
crop, host-plant resistance
Management strategy to break causal agent component - CORRECT ANSWER-
Pesticide applications
How can knowledge of plant disease triangle be used in diagnosis? - CORRECT
ANSWER-Can rule out different pathogens based on host and environment.
Epidemiology - CORRECT ANSWER-Branch of medical science concerned with
the incidence, distribution, and control of diseases that affect large numbers of
people.
, Environmental factors that affect epidemics - CORRECT ANSWER-Temperature,
humidity, moisture, soil pH, nutrient availability, air movement
Importance of time in the development of an epidemic - CORRECT ANSWER-
Epidemics develop very quickly if conditions are favorable. It is critical to reduce
the rate of infection during susceptible life stages of the plant
How does type of reproduction cycle affect development of an epidemic -
CORRECT ANSWER-Polycyclic epidemics can develop much more rapidly than
monocyclic epidemics because of secondary inoculum production.
How does dissemination affect development of an epidemic - CORRECT
ANSWER-Conditions that increase dissemination will accelerate development of
epidemics
Monocyclic disease - CORRECT ANSWER-Disease that only has a primary
infection cycle
Polycyclic disease - CORRECT ANSWER-Disease that produces a secondary
inoculum, and has a secondary infection cycle in addition to a primary infection
cycle
Why are monocyclic diseases less likely to result in serious epidemics? -
CORRECT ANSWER-Controlling primary inoculum is much easier than controlling
QUESTIONS AND CORRECT VERIFIED ANSWERS(complete
solutions) ASSURED SUCCESS/GRADED A+!!!
Biotic factors of plant disease - CORRECT ANSWER-Living organisms (fungi,
bacteria, viruses)
Obligate parasite - CORRECT ANSWER-unable to grow outside of a living host
Facultative saprophyte - CORRECT ANSWER-prefers living organic matter as a
source of nutrition but can adapt to the use of dead organic matter under certain
conditions
Facultative parasite - CORRECT ANSWER-A pathogen that prefers dead
inorganic material, but can also obtain nourishment from living organic material
Biotroph - CORRECT ANSWER-Any parasite that cannot survive in a dead host
and therefore keeps it alive
Necrotroph - CORRECT ANSWER-Parasite that kills host cells
,Koch's Postulates - CORRECT ANSWER-series of guidelines used to identify the
microorganism that causes a specific disease
Plant Disease Definition - CORRECT ANSWER-Abnormal physiological processes
caused by a causal pathogen
Economic significance of plant diseases - CORRECT ANSWER-Losses of yield,
crops, inputs, land
Pathogen - CORRECT ANSWER-Causal agent of disease
Signs of disease - CORRECT ANSWER-Structures of the pathogen
Symptoms of disease - CORRECT ANSWER-Plant response to pathogen infection
Abiotic factors of plant disease - CORRECT ANSWER-Air pollution, temperature,
nutrients
Three components of disease triangle - CORRECT ANSWER-Causal agent,
environment, host
Role of each component of disease triangle - CORRECT ANSWER-All three must
be present for disease to occur. Environment must favor causal agent. Host must
favor causal agent.
,How humans impact each component of disease triangle - CORRECT ANSWER-
Manipulate the environment, host-plant resistance,
preventative/suppressive/erradicative pesticides
Impact of epidemic when one component of disease triangle does not come into
contact with the other two components - CORRECT ANSWER-Slows epidemic to
a halt. Disease spread needs all three components interacting
Management strategy to break environment component - CORRECT ANSWER-
Alter planting dates, remove alternative hosts, alter harvest
Management strategy to break host component - CORRECT ANSWER-Alternate
crop, host-plant resistance
Management strategy to break causal agent component - CORRECT ANSWER-
Pesticide applications
How can knowledge of plant disease triangle be used in diagnosis? - CORRECT
ANSWER-Can rule out different pathogens based on host and environment.
Epidemiology - CORRECT ANSWER-Branch of medical science concerned with
the incidence, distribution, and control of diseases that affect large numbers of
people.
, Environmental factors that affect epidemics - CORRECT ANSWER-Temperature,
humidity, moisture, soil pH, nutrient availability, air movement
Importance of time in the development of an epidemic - CORRECT ANSWER-
Epidemics develop very quickly if conditions are favorable. It is critical to reduce
the rate of infection during susceptible life stages of the plant
How does type of reproduction cycle affect development of an epidemic -
CORRECT ANSWER-Polycyclic epidemics can develop much more rapidly than
monocyclic epidemics because of secondary inoculum production.
How does dissemination affect development of an epidemic - CORRECT
ANSWER-Conditions that increase dissemination will accelerate development of
epidemics
Monocyclic disease - CORRECT ANSWER-Disease that only has a primary
infection cycle
Polycyclic disease - CORRECT ANSWER-Disease that produces a secondary
inoculum, and has a secondary infection cycle in addition to a primary infection
cycle
Why are monocyclic diseases less likely to result in serious epidemics? -
CORRECT ANSWER-Controlling primary inoculum is much easier than controlling
