Final answer:
A desmotubule is the structure that makes up part of a plasmodesma in plant cells. It provides structural support and facilitates the transfer of molecules between adjacent cells.correct option is (D).
Step-by-step explanation:
The structure that makes up part of a plasmodesma is a desmotubule. Plasmodesmata are channels that pass between the cell walls of adjacent plant cells, connecting their cytoplasm and allowing materials to be transported from cell to cell.
The desmotubule is a central tube-like structure that runs through the plasmodesmata, providing structural support and facilitating the transfer of molecules.
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