Final answer:
Phloem is a living vascular tissue in plants that transports organic compounds like sugars and proteins, consisting of conducting cells (sieve elements) and companion cells, as well as phloem parenchyma and fibers for support and storage.
Step-by-step explanation:
The phloem is a key component of the plant's vascular system, responsible for transporting sugars, proteins, and other soluble organic compounds throughout the plant. Unlike the xylem, which is composed of dead cells and transports water and minerals from the roots to the rest of the plant, phloem is composed of living cells.
The primary cells within phloem are sieve elements (conducting cells) and companion cells, along with phloem parenchyma and phloem fibers. The sieve elements are crucial for conducting the photosynthetic products (like sugars) from the leaves to other parts of the plant.
These conducting cells are closely associated with companion cells, which provide metabolic support to the sieve elements. In addition, phloem tissue includes phloem fibers that offer structural support and phloem parenchyma for storage and transport of various substances within the plant.