AP BIOLOGY

Detailed explanation-1: -Sugars produced in sources, such as leaves, need to be delivered to growing parts of the plant via the phloem in a process called translocation, or movement of sugar.

Detailed explanation-2: -Phloem transports carbohydrates, produced by photosynthesis and hydrolysis of reserve compounds, to sink tissues for growth, respiration and storage. At photosynthetic tissues, carbohydrates are loaded into phloem (Rennie and Turgeon 2009), a process that raises the solute concentration.

Detailed explanation-3: -Apart from sugars and hormones, proteins and RNAs are transported via the phloem and contribute to the intercellular communication coordinating growth and development.

Detailed explanation-4: -The sugar in the form of sucrose is moved into the companion cells and then into the living phloem sieve tube cells by active transport. This creates a hypertonic condition in the phloem. Water in xylem vessels adjacent to phloem moves through endosmosis.