AP BIOLOGY

Detailed explanation-1: -Phloem is one of the two tissues that make up the plant’s long-distance transport system, the other being xylem. Phloem translocates water and products of photosynthesis from source tissues to the sink regions where they are utilized or stored.

Detailed explanation-2: -Phloem, the vascular tissue responsible for transporting organic nutrients around the plant body, carries dissolved sugars from the leaves (their site of production) or storage sites to other parts of the plant that require nutrients.

Detailed explanation-3: -While the main role of the phloem tissue is to transport carbohydrates from sources to sinks through the sieve elements, phloem is also composed of parenchyma cells, which play a key role in the storage of water, non-structural carbohydrates and storage proteins (Rosell 2016).

Detailed explanation-4: -The phloem sap contains high quantities of sugars, amino acids, vitamins, and organic and inorganic acids. Sugars and amino acids are the major components of the phloem sap. Sucrose is the predominant sugar in phloem sap.

Detailed explanation-5: -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.