Question

As secondary growth proceeds, in a dicot stem, the diameter

• A. sapwood increases
• B. heartwood increases
• C. both sapwood and heartwood increases
• D. both sapwood and heartwood remains the same

Answer 1

The correct option is B heartwood increases

In young trees and young parts of older trees, all of the wood in the stem is sapwood. But as the tree gets older and its trunk increases in diameter, things change.
The cells nearest the center of the trunk die, but they remain mostly intact. As these older sapwood cells age and die, they become heartwood.
So both sapwood and heartwood are produced but it is only the heartwood which increases in diameter as compared to sapwood. Sapwood width remains fairly constant.