ISA Exam (Certified Arborist) Pre
Questions #2 – PRF With Guaranteed
Pass Solutions 2026-2027 Updated.
What example of tree stressors can be classified as acute? PEB Pg42
- Lightning strike
- insufficient soil
- poor light exposure
- poor moisture conditions - Answer lightning strike
What is most likely NOT a possible cause of deformed leaves? PEB pg 42
- spray injury
- air pollution
- anthracnose
- frost - Answer Air pollution
What tree symptom is NOT likely to be caused by insect infestation? PEB Pg42
- leaf droop
- yellow specks
- off-color foliage
- leaves with a scorched appearance - Answer Leaves with a scorched appearance
What insect listed below is classified as having piercing or sucking mouthparts? PEB Pg43
- leafhoppers
- Beetles
- weevils
- borers - Answer leafhoppers
What herbicide type eliminates the whole of the plant over a short period of time? PEB Pg43
- Pre-emergent
- Contact
- Systemic
- Drench - Answer systemic
,If a tree is suffering from girdling root, what is most likely NOT an advisable action? PEB Pg43
- Remove the largest roots first
- Remove only the smallest roots
- Remove the tree
- None of the above - Answer Remove the largest roots first
Which of the following is NOT classified as an insect? PEB Pg43
- Mites
- Beetles
- Moths
- Caterpillars - Answer Mites
What statement below is FALSE regarding vascular disease? PEB Pg44
- Examples include Dutch elm disease and oak wilt
- it is treatable if found in a reasonable timeframe
- it affects the flow of water and nutrients
- it originates from pathogens entering the plant - Answer it is treatable if found in a
reasonable timeframe
Cellulose and lignin are a defense mechanism against predators by what means? PEB Pg44
- they give off an unfavorable flavor
- They can't be digested
- they have a poor taste
- They are toxic - Answer They can't be digested
A tree exhibits wounded areas of the lower trunk and some physical damage to surface roots.
What is most likely the cause of injury? PEB Pg44
- Frost
- Poor soil conditions
- Lawnmower or machinery
- disease - Answer lawnmower or machinery
What is not one of the primary functions of the energy produced by photosynthesis? PEB Pg44
- maintenance
- growth
,- aesthetics
- defense - Answer aesthetics
What statement below is TRUE regarding how a tree's growth rate and photosynthesis rate will
react to the amount of available resources? PEB Pg45
- The growth rate will be limited before the photosynthesis rate
- The photosynthesis rate will be limited before the growth rate
- The photosynthesis and growth rate become hindered equally with
limited resources
- The photosynthesis rate will not be hindered by limited resources - Answer The growth rate
will be limited before the photosynthesis rate
What single resource has the most detrimental effect on a tree's ability to perform
photosynthesis if limited? PEB Pg45
- Light
- Water
- CO2
- None of the above - Answer None of the above
What extract listed below is NOT an allelochemical classified as a natural insecticide? PEB Pg45
- Nicotine
- Lignin
- Rotenone
- Neem - Answer Lignin
A tree is identified as being in the mortality spiral when what has occurred? PEB Pg45
- the tree has begun to see detrimental stress factors
- the tree has seen an isolated but severely detrimental stress factor
- Cumulative stress factors have yielded a situation where very few actions can save the tree.
- Any combination of stress factors has occurred over time - Answer Cumulative stress factors
have yielded a situation where very few actions can save the tree.
The foundational element of an appropriate response process (ARP) is which of the following?
PEB Pg46
- monitoring
- immediate action
, - establish thresholds
- readily available resources - Answer Monitoring
What is NOT a characteristic of any organism classified as a pest? PEB Pg46
- Threatens health or appearance of plants
- May also contribute to the surrounding landscape
- Provides competition to the local landscape
- Diminishes safety or enjoyment of an area - Answer May also contribute to the surrounding
landscape
Key stressors are identified by what criteria? PEB Pg46
- universally detrimental site conditions
- Retroactive analysis of stress
- Identifying local pests and conditions which may be detrimental.
- species specific historical stressors - Answer Identifying local pests and conditions which may
be detrimental.
Key plants can be identified by which of the following criteria? PEB Pg46
- client specific indications
- specific species
- susceptibility to specific pests
- all of the above - Answer all of the above
For a threshold temperature of 50°, determine the average degree day unit value for
temperature over a 3-day span of 85°,76° and 82°. PEB Pg47
- 22°
- 26°
- 31°
- 45° - Answer 31°
What statement regarding landscapes with a monoculture of plantings is true? PEB Pg47
- They are more susceptible to pest problems
- They are less susceptible to pest problems
- they are equally as susceptible to pest problems
- No correlation exists - Answer they are more susceptible to pest problems
Questions #2 – PRF With Guaranteed
Pass Solutions 2026-2027 Updated.
What example of tree stressors can be classified as acute? PEB Pg42
- Lightning strike
- insufficient soil
- poor light exposure
- poor moisture conditions - Answer lightning strike
What is most likely NOT a possible cause of deformed leaves? PEB pg 42
- spray injury
- air pollution
- anthracnose
- frost - Answer Air pollution
What tree symptom is NOT likely to be caused by insect infestation? PEB Pg42
- leaf droop
- yellow specks
- off-color foliage
- leaves with a scorched appearance - Answer Leaves with a scorched appearance
What insect listed below is classified as having piercing or sucking mouthparts? PEB Pg43
- leafhoppers
- Beetles
- weevils
- borers - Answer leafhoppers
What herbicide type eliminates the whole of the plant over a short period of time? PEB Pg43
- Pre-emergent
- Contact
- Systemic
- Drench - Answer systemic
,If a tree is suffering from girdling root, what is most likely NOT an advisable action? PEB Pg43
- Remove the largest roots first
- Remove only the smallest roots
- Remove the tree
- None of the above - Answer Remove the largest roots first
Which of the following is NOT classified as an insect? PEB Pg43
- Mites
- Beetles
- Moths
- Caterpillars - Answer Mites
What statement below is FALSE regarding vascular disease? PEB Pg44
- Examples include Dutch elm disease and oak wilt
- it is treatable if found in a reasonable timeframe
- it affects the flow of water and nutrients
- it originates from pathogens entering the plant - Answer it is treatable if found in a
reasonable timeframe
Cellulose and lignin are a defense mechanism against predators by what means? PEB Pg44
- they give off an unfavorable flavor
- They can't be digested
- they have a poor taste
- They are toxic - Answer They can't be digested
A tree exhibits wounded areas of the lower trunk and some physical damage to surface roots.
What is most likely the cause of injury? PEB Pg44
- Frost
- Poor soil conditions
- Lawnmower or machinery
- disease - Answer lawnmower or machinery
What is not one of the primary functions of the energy produced by photosynthesis? PEB Pg44
- maintenance
- growth
,- aesthetics
- defense - Answer aesthetics
What statement below is TRUE regarding how a tree's growth rate and photosynthesis rate will
react to the amount of available resources? PEB Pg45
- The growth rate will be limited before the photosynthesis rate
- The photosynthesis rate will be limited before the growth rate
- The photosynthesis and growth rate become hindered equally with
limited resources
- The photosynthesis rate will not be hindered by limited resources - Answer The growth rate
will be limited before the photosynthesis rate
What single resource has the most detrimental effect on a tree's ability to perform
photosynthesis if limited? PEB Pg45
- Light
- Water
- CO2
- None of the above - Answer None of the above
What extract listed below is NOT an allelochemical classified as a natural insecticide? PEB Pg45
- Nicotine
- Lignin
- Rotenone
- Neem - Answer Lignin
A tree is identified as being in the mortality spiral when what has occurred? PEB Pg45
- the tree has begun to see detrimental stress factors
- the tree has seen an isolated but severely detrimental stress factor
- Cumulative stress factors have yielded a situation where very few actions can save the tree.
- Any combination of stress factors has occurred over time - Answer Cumulative stress factors
have yielded a situation where very few actions can save the tree.
The foundational element of an appropriate response process (ARP) is which of the following?
PEB Pg46
- monitoring
- immediate action
, - establish thresholds
- readily available resources - Answer Monitoring
What is NOT a characteristic of any organism classified as a pest? PEB Pg46
- Threatens health or appearance of plants
- May also contribute to the surrounding landscape
- Provides competition to the local landscape
- Diminishes safety or enjoyment of an area - Answer May also contribute to the surrounding
landscape
Key stressors are identified by what criteria? PEB Pg46
- universally detrimental site conditions
- Retroactive analysis of stress
- Identifying local pests and conditions which may be detrimental.
- species specific historical stressors - Answer Identifying local pests and conditions which may
be detrimental.
Key plants can be identified by which of the following criteria? PEB Pg46
- client specific indications
- specific species
- susceptibility to specific pests
- all of the above - Answer all of the above
For a threshold temperature of 50°, determine the average degree day unit value for
temperature over a 3-day span of 85°,76° and 82°. PEB Pg47
- 22°
- 26°
- 31°
- 45° - Answer 31°
What statement regarding landscapes with a monoculture of plantings is true? PEB Pg47
- They are more susceptible to pest problems
- They are less susceptible to pest problems
- they are equally as susceptible to pest problems
- No correlation exists - Answer they are more susceptible to pest problems
