AP BIOLOGY

Detailed explanation-1: -Due to concentration of sugars like sucrose in phloem, it increases the osmotic pressure in the cells of phloem. This makes water to move into phloem cells through osmosis. In turn, it creates more pressure in cells filled with water and thus facilitates its movement through the tissue.

Detailed explanation-2: -The materials like sucrose are transported by phloem sap. This flow of sap occurs in a specialised network of cells, called sieve elements. Phloem transports sucrose and amino acids up and down to the plant.

Detailed explanation-3: -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.

Detailed explanation-4: -The cotransport of a proton with sucrose allows movement of sucrose against its concentration gradient into the companion cells. occurs. From the companion cells, the sugar diffuses into the phloem sieve-tube elements through the plasmodesmata that link the companion cell to the sieve tube elements.

Detailed explanation-5: -This theory suggests that the sucrose is transported into the fruit by active transport, raising the sugar concentration in the fruit relative to the sieve tube. In response to this concentration difference, water will follow the sugar into the fruit by osmosis.