Certified Arborist Examination
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
Question 1
Which of the following tree tissues is primarily responsible for the transport of
water and minerals from the roots to the leaves?
A. Phloem
B. Cambium
C. Xylem
D. Cortex
Answer: C. Xylem. Xylem vessels and tracheids conduct water and dissolved
minerals upward from the roots through the stem to the leaves, driven by
transpiration pull and root pressure. Phloem transports sugars, cambium
produces new vascular tissue, and cortex stores starches.
Question 2
What is the recommended branch bark ridge target for a proper pruning cut?
A. Cut flush with the trunk
B. Cut just outside the branch collar
C. Cut at the midpoint of the branch
D. Cut 6 inches from the trunk
Answer: B. Cut just outside the branch collar. The branch collar contains
specialized tissues that promote wound closure and compartmentalization. Flush
,cuts remove the collar and damage the trunk, while stub cuts leave dead wood
that invites decay.
Question 3
Which soil texture has the highest water-holding capacity?
A. Sand
B. Silt
C. Clay
D. Loam
Answer: C. Clay. Clay particles are microscopic with a high surface area and
numerous micropores, allowing them to retain more water than sand, silt, or
loam. However, much of that water is not plant-available due to high tension.
Loam offers the best balance for tree growth.
Question 4
The term "dieback" in a tree canopy most commonly indicates:
A. Normal seasonal senescence
B. Root damage or vascular dysfunction
C. Excessive sunlight exposure
D. Over-pruning of lower branches
Answer: B. Root damage or vascular dysfunction. Dieback (progressive death of
twigs and branches from the tips inward) is a classic symptom of stress, often
from root compaction, drought, flooding, or pathogen-induced vascular
blockage. Seasonal senescence is uniform and predictable.
Question 5
Which of the following is an example of a biotic agent that causes tree disease?
A. Lightning strike
B. Drought
,C. Fungal pathogen
D. Mechanical wound from a lawnmower
Answer: C. Fungal pathogen. Biotic agents are living organisms, including fungi,
bacteria, viruses, nematodes, and insects. Lightning, drought, and mechanical
wounds are abiotic (non-living) stressors.
Question 6
What is the primary function of mycorrhizal fungi associated with tree roots?
A. Fix atmospheric nitrogen
B. Produce growth hormones
C. Enhance nutrient and water uptake
D. Photosynthesize in low light
Answer: C. Enhance nutrient and water uptake. Mycorrhizae form symbiotic
associations with roots, extending the absorptive surface area via hyphae and
facilitating phosphorus, nitrogen, and water uptake. They do not fix nitrogen
(that is bacteria) nor photosynthesize.
Question 7
When transplanting a balled-and-burlapped tree, the planting hole should be:
A. Twice as deep as the root ball
B. The same depth as the root ball but 2–3 times wider
C. Deeper than the root ball to allow settling
D. Narrower than the root ball to prevent shifting
Answer: B. The same depth as the root ball but 2–3 times wider. Proper planting
depth prevents stem girdling roots and ensures the root flare is visible. Wide
holes encourage lateral root expansion. Deep planting is a leading cause of
transplant failure.
, Question 8
Which pruning method is best for reducing the height of a large tree while
maintaining structural integrity?
A. Topping
B. Drop-crotch pruning
C. Shearing
D. Thinning only
Answer: B. Drop-crotch pruning. This technique reduces height by cutting back to
a lateral branch that is at least one-third the diameter of the removed leader,
preserving natural form and reducing decay risk. Topping is harmful and creates
weak regrowth.
Question 9
The "zone of rapid moisture fluctuation" in a tree's root system is most critical for:
A. Anchorage
B. Fine root survival
C. Bark development
D. Heartwood formation
Answer: B. Fine root survival. Fine roots (feeder roots) are most active in the
upper 12–18 inches of soil, where moisture and oxygen fluctuate. They are
sensitive to drying and flooding, making this zone critical for tree health.
Question 10
What is the proper first-aid response for an electrical contact injury during tree
work?
A. Move the victim away with a dry wooden pole
B. Immediately perform CPR
C. Do not touch the victim until the power is de-energized
D. Apply a tourniquet above the burn
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
Question 1
Which of the following tree tissues is primarily responsible for the transport of
water and minerals from the roots to the leaves?
A. Phloem
B. Cambium
C. Xylem
D. Cortex
Answer: C. Xylem. Xylem vessels and tracheids conduct water and dissolved
minerals upward from the roots through the stem to the leaves, driven by
transpiration pull and root pressure. Phloem transports sugars, cambium
produces new vascular tissue, and cortex stores starches.
Question 2
What is the recommended branch bark ridge target for a proper pruning cut?
A. Cut flush with the trunk
B. Cut just outside the branch collar
C. Cut at the midpoint of the branch
D. Cut 6 inches from the trunk
Answer: B. Cut just outside the branch collar. The branch collar contains
specialized tissues that promote wound closure and compartmentalization. Flush
,cuts remove the collar and damage the trunk, while stub cuts leave dead wood
that invites decay.
Question 3
Which soil texture has the highest water-holding capacity?
A. Sand
B. Silt
C. Clay
D. Loam
Answer: C. Clay. Clay particles are microscopic with a high surface area and
numerous micropores, allowing them to retain more water than sand, silt, or
loam. However, much of that water is not plant-available due to high tension.
Loam offers the best balance for tree growth.
Question 4
The term "dieback" in a tree canopy most commonly indicates:
A. Normal seasonal senescence
B. Root damage or vascular dysfunction
C. Excessive sunlight exposure
D. Over-pruning of lower branches
Answer: B. Root damage or vascular dysfunction. Dieback (progressive death of
twigs and branches from the tips inward) is a classic symptom of stress, often
from root compaction, drought, flooding, or pathogen-induced vascular
blockage. Seasonal senescence is uniform and predictable.
Question 5
Which of the following is an example of a biotic agent that causes tree disease?
A. Lightning strike
B. Drought
,C. Fungal pathogen
D. Mechanical wound from a lawnmower
Answer: C. Fungal pathogen. Biotic agents are living organisms, including fungi,
bacteria, viruses, nematodes, and insects. Lightning, drought, and mechanical
wounds are abiotic (non-living) stressors.
Question 6
What is the primary function of mycorrhizal fungi associated with tree roots?
A. Fix atmospheric nitrogen
B. Produce growth hormones
C. Enhance nutrient and water uptake
D. Photosynthesize in low light
Answer: C. Enhance nutrient and water uptake. Mycorrhizae form symbiotic
associations with roots, extending the absorptive surface area via hyphae and
facilitating phosphorus, nitrogen, and water uptake. They do not fix nitrogen
(that is bacteria) nor photosynthesize.
Question 7
When transplanting a balled-and-burlapped tree, the planting hole should be:
A. Twice as deep as the root ball
B. The same depth as the root ball but 2–3 times wider
C. Deeper than the root ball to allow settling
D. Narrower than the root ball to prevent shifting
Answer: B. The same depth as the root ball but 2–3 times wider. Proper planting
depth prevents stem girdling roots and ensures the root flare is visible. Wide
holes encourage lateral root expansion. Deep planting is a leading cause of
transplant failure.
, Question 8
Which pruning method is best for reducing the height of a large tree while
maintaining structural integrity?
A. Topping
B. Drop-crotch pruning
C. Shearing
D. Thinning only
Answer: B. Drop-crotch pruning. This technique reduces height by cutting back to
a lateral branch that is at least one-third the diameter of the removed leader,
preserving natural form and reducing decay risk. Topping is harmful and creates
weak regrowth.
Question 9
The "zone of rapid moisture fluctuation" in a tree's root system is most critical for:
A. Anchorage
B. Fine root survival
C. Bark development
D. Heartwood formation
Answer: B. Fine root survival. Fine roots (feeder roots) are most active in the
upper 12–18 inches of soil, where moisture and oxygen fluctuate. They are
sensitive to drying and flooding, making this zone critical for tree health.
Question 10
What is the proper first-aid response for an electrical contact injury during tree
work?
A. Move the victim away with a dry wooden pole
B. Immediately perform CPR
C. Do not touch the victim until the power is de-energized
D. Apply a tourniquet above the burn
