Which structure is primarily responsible for growth and support in trees?

The trunk of a tree is primarily responsible for growth and support. It serves as the central structure that elevates the crown, which consists of the leaves and branches, allowing them to access sunlight for photosynthesis. The trunk provides structural integrity, holding the tree upright and allowing it to reach significant heights.

Additionally, the trunk contains various layers, including the cambium, xylem, and phloem, which contribute to the growth of the tree. The cambium is responsible for producing new cells that increase the trunk's diameter, leading to the overall growth of the tree. Xylem transports water and nutrients from the roots to the leaves, while phloem carries the sugars produced by photosynthesis from the leaves to other parts of the tree.

While roots do facilitate nutrient and water uptake from the soil and leaves are important for photosynthesis, the primary role for growth structure and support in a tree is carried out by the trunk. The crown, consisting of foliage and branches, also plays a critical role in photosynthesis and energy production, but it ultimately relies on the trunk for stability and growth support.