Question

what are the sieve tubes and companion cells​

Answer 1

Answer:

Sieve tubes members do not have ribosomes or a nucleus and thus need companion cells to help them function as transport molecules. Companion cells provide Sieve tube members with proteins necessary for signaling and ATP in order to help them transfer molecules between different parts of the plant.

Answer 2

Answer:

Sieve Tubes are a series of cells placed end to end to form a continuous tube. Companion cells are specialized parenchyma cell, located in the phloem of flowering plants and closely associated in development and function with sieve tube elements. They are usually living cells with an elongated structure.