PCA PLANT PATHOGENS EXAM 2026 WITH COMPLETE
ALL QUESTIONS AND CORRECT ANSWERS |VERIFIED//
NEWEST EXAM | | VERIFIED ANSWERS (JUST
RELEASED)
Facultative parasite
A pathogen that prefers dead inorganic material, but
can also obtain nourishment from living organic
material
Biotroph
Any parasite that cannot survive in a dead host and
therefore keeps it alive
Necrotroph
Parasite that kills host cells
Koch's Postulates
series of guidelines used to identify the microorganism
that causes a specific disease
Page | 1
,Three components of disease triangle
Causal agent, environment, host
Role of each component of disease triangle
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
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
Slows epidemic to a halt. Disease spread needs all
three components interacting
Page | 2
,Management strategy to break environment component
Alter planting dates, remove alternative hosts, alter
harvest
Plant Disease Definition
Abnormal physiological processes caused by a causal
pathogen
Economic significance of plant diseases
Losses of yield, crops, inputs, land
Pathogen
Causal agent of disease
Signs of disease
Structures of the pathogen
Symptoms of disease
Page | 3
, Plant response to pathogen infection
Abiotic factors of plant disease
Air pollution, temperature, nutrients
Biotic factors of plant disease
Living organisms (fungi, bacteria, viruses)
Obligate parasite
unable to grow outside of a living host
Facultative saprophyte
prefers living organic matter as a source of nutrition
but can adapt to the use of dead organic matter under
certain conditions
Management strategy to break host component
Alternate crop, host-plant resistance
Page | 4
ALL QUESTIONS AND CORRECT ANSWERS |VERIFIED//
NEWEST EXAM | | VERIFIED ANSWERS (JUST
RELEASED)
Facultative parasite
A pathogen that prefers dead inorganic material, but
can also obtain nourishment from living organic
material
Biotroph
Any parasite that cannot survive in a dead host and
therefore keeps it alive
Necrotroph
Parasite that kills host cells
Koch's Postulates
series of guidelines used to identify the microorganism
that causes a specific disease
Page | 1
,Three components of disease triangle
Causal agent, environment, host
Role of each component of disease triangle
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
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
Slows epidemic to a halt. Disease spread needs all
three components interacting
Page | 2
,Management strategy to break environment component
Alter planting dates, remove alternative hosts, alter
harvest
Plant Disease Definition
Abnormal physiological processes caused by a causal
pathogen
Economic significance of plant diseases
Losses of yield, crops, inputs, land
Pathogen
Causal agent of disease
Signs of disease
Structures of the pathogen
Symptoms of disease
Page | 3
, Plant response to pathogen infection
Abiotic factors of plant disease
Air pollution, temperature, nutrients
Biotic factors of plant disease
Living organisms (fungi, bacteria, viruses)
Obligate parasite
unable to grow outside of a living host
Facultative saprophyte
prefers living organic matter as a source of nutrition
but can adapt to the use of dead organic matter under
certain conditions
Management strategy to break host component
Alternate crop, host-plant resistance
Page | 4
