AP BIOLOGY

Detailed explanation-1: -– The phloem tissue – transports food (sugars and amino acids) from the leaves to the rest of the plant. It is a short and thick tissue made up of living cells. – The transport proteins – are found in the plasma membranes of cells and help to transport molecules across the cell membrane.

Detailed explanation-2: -Phloem tubes can carry sugars and amino acids in a variety of directions; depending on where the source and the sinks are located (sometimes roots can be sources or sinks).

Detailed explanation-3: -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-4: -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-5: -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.