Which tissue transports sugars and other metabolites throughout a plant?

Which tissue transports sugars and other metabolites throughout a plant?

• A. Phloem
• B. Xylem
• C. Cambium Layer
• D. Heartwood

Answer: (A)

Sugars and other metabolites travel throughout a plant mainly through phloem. This tissue forms the living transport system for translocation, carrying photoassimilates from sugar sources like leaves to sinks where they’re used or stored. Phloem is made up of sieve tube elements arranged into continuous tubes, with companion cells that help load and unload sugars and keep the tubes functioning. Movement through phloem, called translocation, relies on a source-to-sink gradient: sugars are actively loaded into the phloem at sources, drawing in water and creating a pressure difference that pushes phloem sap toward sinks where sugars are unloaded and used. Because the flow can go in multiple directions, phloem distributes energy and building blocks to growing tissues, roots, fruits, and storage organs. In contrast, xylem transports water and minerals from roots to shoots, mainly upward, and is largely composed of dead cells. The cambium layer is a meristem that produces new xylem and phloem for secondary growth, while heartwood is older, non-conductive wood inside the stem.

Sugars and other metabolites travel throughout a plant mainly through phloem. This tissue forms the living transport system for translocation, carrying photoassimilates from sugar sources like leaves to sinks where they’re used or stored. Phloem is made up of sieve tube elements arranged into continuous tubes, with companion cells that help load and unload sugars and keep the tubes functioning. Movement through phloem, called translocation, relies on a source-to-sink gradient: sugars are actively loaded into the phloem at sources, drawing in water and creating a pressure difference that pushes phloem sap toward sinks where sugars are unloaded and used. Because the flow can go in multiple directions, phloem distributes energy and building blocks to growing tissues, roots, fruits, and storage organs.

In contrast, xylem transports water and minerals from roots to shoots, mainly upward, and is largely composed of dead cells. The cambium layer is a meristem that produces new xylem and phloem for secondary growth, while heartwood is older, non-conductive wood inside the stem.