Final answer:
Phloem cells transport sugar molecules from the leaves to other parts of the plant through sieve tubes. They have end walls with tiny perforations and are composed of sieve-tube cells and companion cells.
Step-by-step explanation:
Phloem cells are cells that transport sugar molecules from the leaves to other parts of the plant. They are living cells with end walls that have tiny perforations or holes. Phloem tissue is composed of sieve-tube cells and companion cells, with the sieve-tube cells forming long sieve tubes that transport organic substances like sugars and amino acids. The sugars flow from one sieve-tube cell to the next through perforated sieve plates.
The correct statement about phloem cells is A. They transport sugar molecules from the leaves to other parts of the plant. Composed of sieve-tube cells and companion cells, phloem tissue is essential for translocation of sugars.
The statement that best describes the structure and function of phloem cells is: A. They are cells that transport sugar molecules from the leaves to other parts of the plant. Phloem is a type of vascular tissue responsible for the transport of sugars, proteins, and other solutes. Phloem tissue is composed of sieve-tube cells, companion cells, phloem parenchyma, and phloem fibers. The sugars, predominantly sucrose, are produced in the photosynthesizing leaves and then transported through the phloem to various parts of the plant for immediate use or storage.
Sieve-tube cells, arranged end to end, form long seive tubes that conduct these sugars from the leaves to the rest of the plant. Companion cells play a crucial role in providing metabolic support to these sieve-tube cells, as the latter lack significant cellular organelles like a nucleus at maturity. This system of phloem cells allows for the process known as translocation, which is the movement of sugars from the 'source' (typically the leaves) to the 'sink' (areas where the sugars are used or stored).