AP BIOLOGY

Detailed explanation-1: -So, the correct option is ‘Plasmodesmata’.

Detailed explanation-2: -Plasmodesmata connect companion cells to sieve elements and parenchyma cells can connect the sieve tubes to various tissues within the plant. This system between the plasmodesmata, companion cells, and sieve tubes allow for the delivery of necessary metabolites.

Detailed explanation-3: -Final answer: Sieve tubes and companion cells are components of Phloem.

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: -The sugar in the form of sucrose is moved into the companion cells and then into the living phloem sieve tube cells by active transport.