What term describes the visible annual growth in wood due to xylem production?

What term describes the visible annual growth in wood due to xylem production?

• A. Branch collar
• B. Rays
• C. Sapwood
• D. Growth rings

Answer: (D)

Growth rings describe the visible annual growth in wood produced by the xylem each year. As the cambium adds new xylem, spring growth forms large, light-colored earlywood that transports water, followed by slower, denser latewood later in the season. The contrast between these zones creates a ring that can be seen in cross-section and counted to estimate age. In temperate climates the rings are distinct, while in other conditions growth may be less pronounced. The other terms refer to different anatomical features, not the yearly increment pattern: the branch collar is where a branch meets the trunk; rays are radial tissues for storage and transport; sapwood is the outer living xylem that conducts water but isn’t itself the yearly growth pattern.

Growth rings describe the visible annual growth in wood produced by the xylem each year. As the cambium adds new xylem, spring growth forms large, light-colored earlywood that transports water, followed by slower, denser latewood later in the season. The contrast between these zones creates a ring that can be seen in cross-section and counted to estimate age. In temperate climates the rings are distinct, while in other conditions growth may be less pronounced. The other terms refer to different anatomical features, not the yearly increment pattern: the branch collar is where a branch meets the trunk; rays are radial tissues for storage and transport; sapwood is the outer living xylem that conducts water but isn’t itself the yearly growth pattern.