Where is the phloem located in a mature oak tree?

Where is the phloem located in a mature oak tree?

• A. In the center of the trunk and branches
• B. Only in the root hairs
• C. Immediately under the bark
• D. In the mesophyll

Answer: (C)

The main concept is that phloem is the living tissue that transports sugars and is located in the outer parts of a woody stem, just under the bark. In a mature oak, the center of the trunk and branches is mainly xylem (the wood) produced inward by the vascular cambium, while the phloem forms part of the inner bark, lying immediately beneath the outer bark and outside the cambium. This placement is what allows the phloem to move nutrients from the leaves to roots and other tissues. Root hairs are on roots, not stems; mesophyll is leaf tissue, not stem tissue; and the center of the trunk is not where phloem resides.

The main concept is that phloem is the living tissue that transports sugars and is located in the outer parts of a woody stem, just under the bark. In a mature oak, the center of the trunk and branches is mainly xylem (the wood) produced inward by the vascular cambium, while the phloem forms part of the inner bark, lying immediately beneath the outer bark and outside the cambium. This placement is what allows the phloem to move nutrients from the leaves to roots and other tissues. Root hairs are on roots, not stems; mesophyll is leaf tissue, not stem tissue; and the center of the trunk is not where phloem resides.