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. The points of sugar delivery, such as roots, young shoots, and developing seeds, are called sinks.

Detailed explanation-2: -Phloem is a highly specialised vascular tissue that forms an interconnected network of continuous strands throughout a plant’s body. It transports sugars, nutrients, and a range of signalling molecules between leaves, roots, flowers, and fruits. As a result, phloem is central to plant function.

Detailed explanation-3: -The larger molecules cannot move back to phloem parenchyma cells (PP) and are transferred and accumulated in sieve tubes. In apoplast-loading species, sucrose reaches phloem parenchyma cells through plasmodesmata. Sucrose is loaded and accumulates in the phloem by passing through the apoplast between the PP and the CC.

Detailed explanation-4: -Translocation is the movement of elements within a plant from leaves to other tissue. Plants’ phloem, a type of vascular tissue, is where translocation takes place. Sugars that are produced by photosynthesis or that are stored in plant tissues like roots, bulbs, and tubers are examples of sugar sources.

Detailed explanation-5: -Translocation occurs in the phloem tissue, which consists of tube-like structures called phloem vessels. These phloem vessels run from the leaves into every other part of the plant and are responsible for transporting dissolved organic solutes, such as sucrose and amino acids, from the sources to the sinks.