In dicotyledonous stem, each companion cell is founded beside the

In a dicotyledonous stem, each companion cell is found beside the sieve tube. Sieve tubes are a type of specialized plant cell that forms a part of the phloem, which is responsible for transporting sugars and other organic compounds throughout the plant. Companion cells are a type of plant cell that are closely associated with sieve tube cells. They are responsible for supporting the sieve tube cells and facilitating the movement of sugars and other organic compounds through the phloem. During development, the companion cells and sieve tube cells are derived from the same mother cell. As they mature, the companion cells remain closely associated with the sieve tube cells and are always found adjacent to them. This close association allows the companion cells to provide the sieve tube cells with the energy and nutrients they need to carry out their transport function. Therefore, the correct answer to the question is the sieve tube, as each companion cell is found beside it in the dicotyledonous stem.