ISA CERTIFIED ARBORIST PRACTICE
EXAM QUESTIONS AND ANSWERS 2026
VERIFIED.
What is the total time allowed for the ISA Certified Arborist exam? - ANS 210 minutes (3.5
hours)
How many total questions are on the ISA Certified Arborist exam? - ANS 200 questions
How many questions on the exam are not scored? - ANS 20 questions
What is the penalty for guessing on the ISA exam? - ANS There is no penalty for guessing
Which knowledge area accounts for the highest percentage of exam questions? -
ANS Pruning (16%)
What percentage of the exam covers Safe Work Practices? - ANS 15%
What percentage of the exam covers Tree Risk Management? - ANS 13%
What percentage of the exam covers Soil Management and Diagnosis/Treatment? - ANS 12%
each
@COPYRIGHT ALL RIGHTS RESERVED PAGE 1 OF 30
,What are the three main properties of soil that must be understood for the exam? -
ANS Physical, chemical, and biological properties
Why is proper tree identification important for an arborist? - ANS To diagnose problems,
recommend care, and perform tree work
What are two potential issues with using common names for trees? - ANS They can be
inconsistent, regional, or ambiguous compared to scientific names
What are some examples of morphological characteristics used for tree identification? -
ANS Leaf arrangement, leaf type, leaf shape, leaf margin, and twig/bud characteristics
What is the primary goal of post-planting care? - ANS To ensure survival, growth, and good
structure of newly planted trees
What are the key components of site safety during tree work? - ANS Traffic control, work
zone management, and drop zone management
What must an arborist do when working near electric wires? - ANS Maintain safe distances
and be aware of electrical hazards
What is the purpose of a job briefing? - ANS To plan the work and ensure all crew members
understand the tasks and safety protocols
What are the required categories of PPE for tree work? - ANS Head, eye, hearing, footwear,
and chain saw protection
What is the purpose of a command and response communication system? - ANS To ensure
clear and effective communication between crew members
What are the three emergency response procedures required for an arborist? - ANS Calling
authorities, first aid/CPR, and aerial rescue
@COPYRIGHT ALL RIGHTS RESERVED PAGE 2 OF 30
, What is the difference between gymnosperms and angiosperms in terms of anatomy? -
ANS They differ in the anatomical structure of their trunks, stems, leaves, and roots
How does palm anatomy differ from that of typical trees? - ANS Palms have a distinct
anatomical structure compared to other trees
What is the 'mortality spiral' in tree biology? - ANS The process of decline and senescence
leading to tree death
What is the function of photosynthesis in trees? - ANS To convert light energy into chemical
energy for growth and maintenance
How do trees transport water? - ANS They move water from the roots up to the leaves
What are the stages of a tree's life cycle? - ANS From juvenile to veteran
What is the purpose of structural soils? - ANS To provide support for infrastructure while
allowing for root growth
What is the ideal soil ratio for solids to pore space? - ANS 50:50
What is the scientific name for the oak tree genus? - ANS Quercus
Which of the following is not one of the five major categories of soil horizons: O, E, N, or B? -
ANS N
What is the difference in magnitude of acidity between a pH of 4 and a pH of 7? - ANS 1000
@COPYRIGHT ALL RIGHTS RESERVED PAGE 3 OF 30
EXAM QUESTIONS AND ANSWERS 2026
VERIFIED.
What is the total time allowed for the ISA Certified Arborist exam? - ANS 210 minutes (3.5
hours)
How many total questions are on the ISA Certified Arborist exam? - ANS 200 questions
How many questions on the exam are not scored? - ANS 20 questions
What is the penalty for guessing on the ISA exam? - ANS There is no penalty for guessing
Which knowledge area accounts for the highest percentage of exam questions? -
ANS Pruning (16%)
What percentage of the exam covers Safe Work Practices? - ANS 15%
What percentage of the exam covers Tree Risk Management? - ANS 13%
What percentage of the exam covers Soil Management and Diagnosis/Treatment? - ANS 12%
each
@COPYRIGHT ALL RIGHTS RESERVED PAGE 1 OF 30
,What are the three main properties of soil that must be understood for the exam? -
ANS Physical, chemical, and biological properties
Why is proper tree identification important for an arborist? - ANS To diagnose problems,
recommend care, and perform tree work
What are two potential issues with using common names for trees? - ANS They can be
inconsistent, regional, or ambiguous compared to scientific names
What are some examples of morphological characteristics used for tree identification? -
ANS Leaf arrangement, leaf type, leaf shape, leaf margin, and twig/bud characteristics
What is the primary goal of post-planting care? - ANS To ensure survival, growth, and good
structure of newly planted trees
What are the key components of site safety during tree work? - ANS Traffic control, work
zone management, and drop zone management
What must an arborist do when working near electric wires? - ANS Maintain safe distances
and be aware of electrical hazards
What is the purpose of a job briefing? - ANS To plan the work and ensure all crew members
understand the tasks and safety protocols
What are the required categories of PPE for tree work? - ANS Head, eye, hearing, footwear,
and chain saw protection
What is the purpose of a command and response communication system? - ANS To ensure
clear and effective communication between crew members
What are the three emergency response procedures required for an arborist? - ANS Calling
authorities, first aid/CPR, and aerial rescue
@COPYRIGHT ALL RIGHTS RESERVED PAGE 2 OF 30
, What is the difference between gymnosperms and angiosperms in terms of anatomy? -
ANS They differ in the anatomical structure of their trunks, stems, leaves, and roots
How does palm anatomy differ from that of typical trees? - ANS Palms have a distinct
anatomical structure compared to other trees
What is the 'mortality spiral' in tree biology? - ANS The process of decline and senescence
leading to tree death
What is the function of photosynthesis in trees? - ANS To convert light energy into chemical
energy for growth and maintenance
How do trees transport water? - ANS They move water from the roots up to the leaves
What are the stages of a tree's life cycle? - ANS From juvenile to veteran
What is the purpose of structural soils? - ANS To provide support for infrastructure while
allowing for root growth
What is the ideal soil ratio for solids to pore space? - ANS 50:50
What is the scientific name for the oak tree genus? - ANS Quercus
Which of the following is not one of the five major categories of soil horizons: O, E, N, or B? -
ANS N
What is the difference in magnitude of acidity between a pH of 4 and a pH of 7? - ANS 1000
@COPYRIGHT ALL RIGHTS RESERVED PAGE 3 OF 30
