EVERYDAY SCIENCE

Detailed explanation-1: -Plasmodesmata connect companion cells to sieve elements and parenchyma cells can connect the sieve tubes to various tissues within the plant. This system between the plasmodesmata, companion cells, and sieve tubes allow for the delivery of necessary metabolites.

Detailed explanation-2: -Phloem sap travels through perforations called sieve tube plates. Neighboring companion cells carry out metabolic functions for the sieve-tube elements and provide them with energy.

Detailed explanation-3: -Phloem: It is a complex tissue in the vascular system of higher plants that consists mainly of sieve tubes and elongated parenchyma cells usually with fibers and that functions in translocation and in support and storage. Sieve tubes and companion cells are the elements of phloem.

Detailed explanation-4: -Companion cells surround sieve elements. The function of companion cells, a type of parenchyma cells, is to support sieve elements by carrying out cell metabolism and regulation.

Detailed explanation-5: -Since the sieve elements are incapable of self supported survival due to the lack of a nucleous and other organells, companion cells support their sieve element throughout its lifetime. Companion cells are characterized by a dense cytoplasm and a high number of mitochondria.