The Main Phloem Conducting Cells Are

Question

The main phloem conducting cells are
A) companion cells.
B) tracheids.
C) sieve tube elements.
D) stomata.
E) vessel elements.

Accepted Answer

Sieve tube elements are the main phloem conducting cells that transport organic nutrients (such as sugars) throughout the plant. They are elongated cells that are connected end-to-end to form sieve tubes. These cells lack nuclei, ribosomes, and a distinct vacuole, but have specialized sieve plates on their ends which allow for the movement of nutrients between adjacent cells. Companion cells, which are closely associated with sieve tube elements, help to maintain the metabolic functions and proper functioning of sieve tubes. Tracheids and vessel elements are types of cells found in xylem tissue, which transports water and minerals from the roots to the rest of the plant. Stomata are specialized pores found in the epidermis of leaves and stems that regulate gas exchange and transpiration.