Certified Arborist Test Tree Biology and Structure 2

Question 1

What is the primary function of the cambium layer in a tree?

Accepted Answer

Producing new xylem and phloem cells

Answer

The cambium is a meristematic layer that produces new xylem (wood) to the inside and new phloem (bark) to the outside, enabling secondary growth and diameter increase.

Question 2

Which of the following best describes the process of transpiration in trees?

Accepted Answer

Loss of water vapor from leaf stomata driving sap ascent

Answer

Transpiration is the evaporation of water from leaf stomata, which creates a tension that pulls water upward through the xylem from roots to leaves — the cohesion-tension mechanism.

Question 3

What is the CODIT model primarily used to describe?

Accepted Answer

Compartmentalization of Decay in Trees

Answer

CODIT (Compartmentalization of Decay in Trees), developed by Dr. Alex Shigo, describes the four walls of chemical and physical resistance trees form to contain decay following wounding.

Question 4

In tree physiology, what is 'girdling' and what is its primary consequence?

Accepted Answer

Disruption of the phloem causing starvation of roots

Answer

Girdling involves removal or damage to the phloem layer completely around a tree's circumference, preventing sugars from reaching roots and eventually causing root starvation and tree death.

Question 5

What is the role of lenticels on tree bark?

Accepted Answer

Allowing gas exchange between internal tissues and the atmosphere

Answer

Lenticels are small, porous openings in the bark of woody plants that allow oxygen and carbon dioxide to diffuse in and out of internal living tissues for cellular respiration.

Certified Arborist Test Practice Test

Certified Arborist Test Practice Test

Certified Arborist Test Tree Biology and Structure 2