HORTICULTURE

Detailed explanation-1: -Phloem: Active transport of sucrose from source cells into phloem sieve tube elements (energy required)

Detailed explanation-2: -At the sources (usually the leaves), sugar molecules are moved into the sieve elements (phloem cells) through active transport. Water follows the sugar molecules into the sieve elements through osmosis (since water passively diffuses into regions of higher solute concentration).

Detailed explanation-3: -The transportation occurs in the direction of the source to sink. Transport of organic solutes from one part of the plant to the other through phloem sieve tubes is called translocation of organic solvents.

Detailed explanation-4: -depends upon the active transport of sugars into the sieve-tube elements: Sugars are actively loaded into phloem at source tissues, thus contributing to the pressure that drives the contents of phloem toward sinks by drawing water from the xylem and into the phloem to create a turgor pressure gradient.