GENERAL KNOWLEDGE

Detailed explanation-1: -Phloem is a complex tissue which is concerned with the transport of food materials from leaves to other plant parts. Phloem is composed of sieve tube elements, companion cells, phloem parenchyma and phloem fibres. sieve tubes are longitudinally arranged cells. It is seen associated with the companion cells.

Detailed explanation-2: -…angiosperms are sieve tubes and companion cells found in the phloem (see angiosperm: Vascular tissue). In other vascular plants, parenchyma cells function in the same way as companion cells (that is, as the sieve cell’s living protoplasm), but they are not derived from the same mother cell as the sieve…

Detailed explanation-3: -Sieve tubes and companion cells are components of xylem tissue.

Detailed explanation-4: -In Gymnosperms, the phloem lacks both the sieve tube and the corresponding cells. Instead they contain sieve cells for food material conduction. The Sieve element is the phloem conductive element. Companion Cells for the sieve function are “life support” cells.