Which tissue is primarily responsible for transporting sugars from leaves to other parts of the plant?

Which tissue is primarily responsible for transporting sugars from leaves to other parts of the plant?

• A. Phloem
• B. Xylem
• C. Cambium
• D. Pith

Answer: (A)

Sugars are moved through the phloem in a process called translocation. The leaves produce sugars during photosynthesis, and the phloem transports these sugars from source tissues (like mature leaves) to sink tissues (growing shoots, roots, fruits) that need energy. The phloem’s sieve tube elements, aided by companion cells, actively load sugars such as sucrose into the tubes. This creates a high solute concentration, pulling water from the xylem by osmosis and generating pressure that pushes the phloem sap along the tube to where it’s needed. At the destination, sugars are unloaded and used or stored. Xylem, by contrast, carries water and minerals upward from the roots and is made of mostly dead cells. Cambium is a growth layer that produces new xylem and phloem for secondary growth, and pith is central ground tissue not involved in long-distance transport.

Sugars are moved through the phloem in a process called translocation. The leaves produce sugars during photosynthesis, and the phloem transports these sugars from source tissues (like mature leaves) to sink tissues (growing shoots, roots, fruits) that need energy. The phloem’s sieve tube elements, aided by companion cells, actively load sugars such as sucrose into the tubes. This creates a high solute concentration, pulling water from the xylem by osmosis and generating pressure that pushes the phloem sap along the tube to where it’s needed. At the destination, sugars are unloaded and used or stored.

Xylem, by contrast, carries water and minerals upward from the roots and is made of mostly dead cells. Cambium is a growth layer that produces new xylem and phloem for secondary growth, and pith is central ground tissue not involved in long-distance transport.