SSC MTS EXAM

Detailed explanation-1: -Final answer: The form of sugar transported through phloem is sucrose.

Detailed explanation-2: -Sucrose, RFOs and polyols are transported in the sieve tubes to the sink organs in the transport phloem. All along the path, they can be leaked from and reloaded into the phloem via the same mechanism (not shown). Sucrose is unloaded into the release phloem where the hydrostatic pressure is supposed to be lower.

Detailed explanation-3: -Sucrose transport is favorable for the following reasons: (i) 1 mol sucrose contains more energy than 1 mol of a monosaccharide such as glucose or fructose, thus using the disaccharide is more energy efficient for transport and storage.

Detailed explanation-4: -Material like sucrose is transferred into phloem tissue using energy from ATP. This increases the osmotic pressure of the tissue causing water to move into it. This pressure moves the material in the phloem to tissues which have less pressure. This allows the phloem to move material according to the plant’s needs.