PCA PLANT PATHOGENS EXAM NEWEST 2025 COMPLETE QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+
Plant Disease Definition - (answer)Abnormal physiological processes caused by a causal pathogen
Economic significance of plant diseases - (answer)Losses of yield, crops, inputs, land
Pathogen - (answer)Causal agent of disease
Signs of disease - (answer)Structures of the pathogen
Symptoms of disease - (answer)Plant response to pathogen infection
Abiotic factors of plant disease - (answer)Air pollution, temperature, nutrients
Biotic factors of plant disease - (answer)Living organisms (fungi, bacteria, viruses)
Obligate parasite - (answer)unable to grow outside of a living host
Facultative saprophyte - (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 - (answer)A pathogen that prefers dead inorganic material, but can also obtain
nourishment from living organic material
Biotroph - (answer)Any parasite that cannot survive in a dead host and therefore keeps it alive
Necrotroph - (answer)Parasite that kills host cells
Koch's Postulates - (answer)series of guidelines used to identify the microorganism that causes a specific
disease
,PCA PLANT PATHOGENS EXAM NEWEST 2025 COMPLETE QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+
Three components of disease triangle - (answer)Causal agent, environment, host
Role of each component of disease triangle - (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 - (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 - (answer)Slows epidemic to a halt. Disease spread needs all three components
interacting
Management strategy to break environment component - (answer)Alter planting dates, remove
alternative hosts, alter harvest
Management strategy to break host component - (answer)Alternate crop, host-plant resistance
Management strategy to break causal agent component - (answer)Pesticide applications
How can knowledge of plant disease triangle be used in diagnosis? - (answer)Can rule out different
pathogens based on host and environment.
Epidemiology - (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 - (answer)Temperature, humidity, moisture, soil pH,
nutrient availability, air movement
,PCA PLANT PATHOGENS EXAM NEWEST 2025 COMPLETE QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+
Importance of time in the development of an epidemic - (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 - (answer)Polycyclic epidemics
can develop much more rapidly than monocyclic epidemics because of secondary inoculum production.
How does dissemination affect development of an epidemic - (answer)Conditions that increase
dissemination will accelerate development of epidemics
Monocyclic disease - (answer)Disease that only has a primary infection cycle
Polycyclic disease - (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? - (answer)Controlling primary
inoculum is much easier than controlling primary and secondary inoculum. Once primary inoculum is
controlled and dissemination is controlled, the disease essentially stops developing.
How do sanitation practices impact monocyclic diseases? - (answer)Epidemic may be delayed, but
severe epidemic can still occur if environmental conditions are favorable for disease development
How do sanitation practices impact polycyclic diseases? - (answer)Reducing primary inoculum may
reduce the amount of secondary inoculum produced. If rate of infection is high, there is little effect. But
if rate of infection is low, it may reduce an epidemic
Formae specialis - (answer)Indicates a fungus is adapted to a specific host
Incubation period - (answer)interval between initial infection and first signs and symptoms
, PCA PLANT PATHOGENS EXAM NEWEST 2025 COMPLETE QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+
Infection - (answer)Invasion of a plant by a pathogen
Infestation - (answer)Large numbers of pathogen present causing damage
Inoculum - (answer)Infecting agent of a pathogen
Latent infection - (answer)infection in which the infectious agent is present but not causing symptoms
Mummy - (answer)Dead, shriveled fruit that a pathogen may overwinter in
Overwintering - (answer)the process by which some organisms pass through or wait out the winter
season
Pathovar - (answer)subdivision of a plant pathogenic bacterial species defined by host range
Propagule - (answer)Portion of a plant which is used to generate a new plant
Race - (answer)Strain of a virus adapted to a specific host
Soil inhabitant/soil resident - (answer)Pathogen that can survive in the soil for long periods of time
Soil transient/soil invader - (answer)Pathogen that can survive in the soil for a short period of time
Vector - (answer)An organism that can transport and transmit a disease
Apothecium - (answer)cup-shaped ascocarp
DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+
Plant Disease Definition - (answer)Abnormal physiological processes caused by a causal pathogen
Economic significance of plant diseases - (answer)Losses of yield, crops, inputs, land
Pathogen - (answer)Causal agent of disease
Signs of disease - (answer)Structures of the pathogen
Symptoms of disease - (answer)Plant response to pathogen infection
Abiotic factors of plant disease - (answer)Air pollution, temperature, nutrients
Biotic factors of plant disease - (answer)Living organisms (fungi, bacteria, viruses)
Obligate parasite - (answer)unable to grow outside of a living host
Facultative saprophyte - (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 - (answer)A pathogen that prefers dead inorganic material, but can also obtain
nourishment from living organic material
Biotroph - (answer)Any parasite that cannot survive in a dead host and therefore keeps it alive
Necrotroph - (answer)Parasite that kills host cells
Koch's Postulates - (answer)series of guidelines used to identify the microorganism that causes a specific
disease
,PCA PLANT PATHOGENS EXAM NEWEST 2025 COMPLETE QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+
Three components of disease triangle - (answer)Causal agent, environment, host
Role of each component of disease triangle - (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 - (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 - (answer)Slows epidemic to a halt. Disease spread needs all three components
interacting
Management strategy to break environment component - (answer)Alter planting dates, remove
alternative hosts, alter harvest
Management strategy to break host component - (answer)Alternate crop, host-plant resistance
Management strategy to break causal agent component - (answer)Pesticide applications
How can knowledge of plant disease triangle be used in diagnosis? - (answer)Can rule out different
pathogens based on host and environment.
Epidemiology - (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 - (answer)Temperature, humidity, moisture, soil pH,
nutrient availability, air movement
,PCA PLANT PATHOGENS EXAM NEWEST 2025 COMPLETE QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+
Importance of time in the development of an epidemic - (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 - (answer)Polycyclic epidemics
can develop much more rapidly than monocyclic epidemics because of secondary inoculum production.
How does dissemination affect development of an epidemic - (answer)Conditions that increase
dissemination will accelerate development of epidemics
Monocyclic disease - (answer)Disease that only has a primary infection cycle
Polycyclic disease - (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? - (answer)Controlling primary
inoculum is much easier than controlling primary and secondary inoculum. Once primary inoculum is
controlled and dissemination is controlled, the disease essentially stops developing.
How do sanitation practices impact monocyclic diseases? - (answer)Epidemic may be delayed, but
severe epidemic can still occur if environmental conditions are favorable for disease development
How do sanitation practices impact polycyclic diseases? - (answer)Reducing primary inoculum may
reduce the amount of secondary inoculum produced. If rate of infection is high, there is little effect. But
if rate of infection is low, it may reduce an epidemic
Formae specialis - (answer)Indicates a fungus is adapted to a specific host
Incubation period - (answer)interval between initial infection and first signs and symptoms
, PCA PLANT PATHOGENS EXAM NEWEST 2025 COMPLETE QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+
Infection - (answer)Invasion of a plant by a pathogen
Infestation - (answer)Large numbers of pathogen present causing damage
Inoculum - (answer)Infecting agent of a pathogen
Latent infection - (answer)infection in which the infectious agent is present but not causing symptoms
Mummy - (answer)Dead, shriveled fruit that a pathogen may overwinter in
Overwintering - (answer)the process by which some organisms pass through or wait out the winter
season
Pathovar - (answer)subdivision of a plant pathogenic bacterial species defined by host range
Propagule - (answer)Portion of a plant which is used to generate a new plant
Race - (answer)Strain of a virus adapted to a specific host
Soil inhabitant/soil resident - (answer)Pathogen that can survive in the soil for long periods of time
Soil transient/soil invader - (answer)Pathogen that can survive in the soil for a short period of time
Vector - (answer)An organism that can transport and transmit a disease
Apothecium - (answer)cup-shaped ascocarp
