What is the significance of the cambium layer in trees?

• A. It is responsible for the growth of the tree and can be damaged by insects.
• B. It stores nutrients for winter.
• C. It forms heartwood.
• D. It anchors the tree's roots.

Answer: (A)

The main idea is that the cambium is the growth layer that drives a tree’s diameter growth. This thin band of actively dividing cells sits between the wood (xylem) and the bark (phloem). As it divides, it adds new xylem inward and new phloem outward, which is how the tree thickens each year.

Because the cambium is the tissue that keeps producing new vascular cells, damage to it—such as from insects that chew through the layer or girdle the stem—can halt growth and disrupt the transport of water, nutrients, and sugars, potentially harming or killing parts of the tree.

The other statements miss the function of cambium: storage of nutrients happens in other tissues, not the cambium; heartwood forms from older xylem rather than being formed by cambial activity; and root anchorage depends on roots and their tissues, not on the cambium.