ISA Certified Arborist Practice Exam

What role does the cambium layer play in a tree?

1. It stores sugars produced during photosynthesis

2. It produces new wood cells and bark

3. It anchors the tree to the soil

4. It transports water and nutrients from roots to leaves

The correct answer is: It produces new wood cells and bark

The cambium layer is a vital part of a tree's anatomy that plays a crucial role in its growth and development. It is a thin layer of actively dividing cells located between the bark and the wood. The primary function of the cambium is to produce new cells that contribute to the growth of both the wood (xylem) and the bark (phloem). This process allows the tree to increase in diameter over time, a phenomenon known as secondary growth. As the cambium divides, it produces new xylem cells toward the inside of the tree, which are responsible for transporting water and nutrients from the roots to the leaves. Simultaneously, it produces new phloem cells toward the outside, aiding in the transportation of sugars and other products of photosynthesis from the leaves to the rest of the tree. The other options refer to different functions within a tree's physiology. While the storage of sugars (as in the first option) occurs mainly in the phloem and other tissues, the anchoring of the tree to the soil (as mentioned in the third option) is primarily the role of the root system. The transport of water and nutrients (as described in the fourth option) happens in the xylem but is