Question

What are companion cell and phloem fibers?

Answer 1

In biology, a cell is a basic membrane-bound unit that contains the fundamental molecules of life and is made up of which all living things are made. A single cell, such as a bacterium or yeast, is frequently a complete organism in and of itself. As cells mature, they develop specialized functions.

Complete answer:
Cellular companionship A type of cell found in flowering plants' phloem. Each companion cell is usually close to a sieve element. Its function is unknown, but it appears to regulate the activity of the adjacent sieve element and to participate in sugar loading and unloading. Albuminous cells, which are found in gymnosperms, serve a similar function.
Sugar and amino acids are moved into and out of the sieve elements by companion cells. Active transport is used by transmembrane proteins in tissues such as leaf companion cells to take up sugars such as sucrose and amino acids.
The vascular tissue that performs the function of translocation is the phloem (i.e. the process of transporting photosynthate materials from the photosynthetic plant organs to various parts of the plant). The major components of the phloem are as follows: (1) sieve elements, (2) companion cells, (3) phloem sclerenchyma, and (4) phloem parenchyma.
The phloem fiber is both narrow and long. It can be found in both the primary and secondary phloem. However, it is rarely found in the metaphloem. The phloem fibers in secondary phloem from bast fibers, some of which are commercially important.

Note:
The phloem cells are adapted to their function. Each sieve tube has a perforated end, so its cytoplasm connects one cell to the next. Companion cells - the transport of substances in the phloem necessitates the use of energy. This energy is provided by one or more companion cells attached to each sieve tube.