Certified Arborist Test Tree Biology and Structure 1

Question 1

Which tissue is responsible for transporting water and dissolved minerals from the roots upward through a tree?

Accepted Answer

Xylem

Answer

Xylem is the vascular tissue that conducts water and dissolved minerals (sap) upward from the roots to the leaves. Phloem, by contrast, transports photosynthate (sugars) downward from the leaves.

Question 2

What term describes the dead, darkened wood at the center of a tree trunk that no longer conducts water but provides structural support?

Accepted Answer

Heartwood

Answer

Heartwood is the central column of older, non-conducting xylem. Its cells are dead and often impregnated with extractives that darken it, but it provides the tree's primary structural rigidity.

Question 3

Which of the following correctly describes the role of lenticels on a tree's bark?

Accepted Answer

They allow gas exchange between internal tissues and the atmosphere

Answer

Lenticels are small pores in the bark that permit oxygen to diffuse into living cells and carbon dioxide to escape, performing a function analogous to stomata in leaves.

Question 4

In tree anatomy, what is the primary purpose of root hairs?

Accepted Answer

Greatly increasing the surface area for water and nutrient absorption

Answer

Root hairs are thin-walled extensions of epidermal cells near root tips. Their enormous combined surface area maximizes contact with soil moisture and dissolved minerals, dramatically improving absorption efficiency.

Question 5

What name is given to the protective boundary zone a tree forms between healthy tissue and a wound or decayed area?

Accepted Answer

Reaction zone

Answer

A reaction zone (also called a barrier zone in CODIT) is chemically and structurally altered wood that the tree produces to resist the spread of decay. It forms behind the wound and represents the most important of the four walls in compartmentalization.

Certified Arborist Test Practice Test

Certified Arborist Test Practice Test

Certified Arborist Test Tree Biology and Structure 1