Answer:
In woody stemmed plants, the outer living section is called the sapwood. The sapwood is the active, living part of the wood that transports water and nutrients from the roots to the leaves. It is typically lighter in color compared to the inner heartwood.
The sapwood plays a vital role in the plant's growth and development. It is responsible for conducting water and minerals absorbed by the roots upwards to the leaves for photosynthesis. The sapwood also helps in storing and distributing sugars produced during photosynthesis to other parts of the plant.
As the sapwood ages, it eventually transforms into heartwood. The heartwood is the inner, non-living section of the wood that provides structural support to the plant. Unlike the sapwood, the heartwood no longer conducts water or nutrients. Instead, it becomes hardened and darker in color due to the accumulation of substances such as resins and tannins.
In summary, the outer living section in woody stemmed plants is the sapwood. It is responsible for the transportation of water, nutrients, and sugars, while the heartwood provides structural support.