EVERYDAY SCIENCE

Detailed explanation-1: -Function of companion cell is to load sugar and amino acids into sieve elements. These cells use transmembrane proteins to take up these molecules by active transport.

Detailed explanation-2: -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. It is the companion cells that helps transport carbohydrates from outside the cells into the sieve tube elements.

Detailed explanation-3: -Companion cells are found along with sieve tube elements in the phloem. The main function of companion cells is to maintain pressure gradient in the sieve tube elements.

Detailed explanation-4: -Companion cells, or albuminous cells in non-flowering vascular plants, are another specialized type of parenchyma and carry out the cellular functions of adjacent sieve elements; they typically have a larger number of mitochondria and ribosomes than other parenchyma cells.

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.