Which process moves sugars through the phloem from production areas to storage or to respiration and growth?

Which process moves sugars through the phloem from production areas to storage or to respiration and growth?

• A. Translocation
• B. Transpiration
• C. Evaporation
• D. Respiration

Answer: (A)

Sugars produced in leaves are moved through the phloem to storage sites or to tissues where they’re needed for respiration and growth. This movement is called translocation. It happens when sugars are actively loaded into phloem sieve tubes at the source, drawing water from the xylem by osmosis and creating a pressure that pushes the sugary sap toward sinks. There, sugars are unloaded and used for storage or for energy and development. Translocation explains how energy-rich sugars travel to parts of the plant that aren’t photosynthesizing. Transpiration, by contrast, is the loss of water vapor from leaves and mainly helps pull water up the xylem, not move sugars in the phloem. Evaporation is just a phase change of a substance from liquid to vapor, not a transport process. Respiration is the cellular process of releasing energy from sugars, not a means of transporting them.

Sugars produced in leaves are moved through the phloem to storage sites or to tissues where they’re needed for respiration and growth. This movement is called translocation. It happens when sugars are actively loaded into phloem sieve tubes at the source, drawing water from the xylem by osmosis and creating a pressure that pushes the sugary sap toward sinks. There, sugars are unloaded and used for storage or for energy and development. Translocation explains how energy-rich sugars travel to parts of the plant that aren’t photosynthesizing.

Transpiration, by contrast, is the loss of water vapor from leaves and mainly helps pull water up the xylem, not move sugars in the phloem. Evaporation is just a phase change of a substance from liquid to vapor, not a transport process. Respiration is the cellular process of releasing energy from sugars, not a means of transporting them.