FFA Horticulture CDE General Practice Exam

What are the water-conducting cells in a plant stem called?

1. Phloem

2. Xylem

3. Cortex

4. Parenchyma

The correct answer is: Xylem

The correct answer is xylem, which is responsible for the transport of water and dissolved minerals from the roots to other parts of the plant. Xylem cells are specialized for this function and are structured to allow the efficient movement of water, typically through a series of long, thin tubes that facilitate capillary action. In the context of plant structure, xylem is crucial for maintaining turgor pressure, which supports the plant's structure and overall health. The movement of water through xylem also plays a vital role in nutrient transport and cooling the plant through transpiration. Phloem, while also essential to plant function, serves a different purpose, transporting sugars and other organic compounds produced during photosynthesis. The cortex is a layer of tissue in the plant stem that primarily provides storage and support, while parenchyma cells are versatile and play various roles, including storage and tissue repair, but they are not specialized for water conduction like xylem. Thus, understanding the unique functions of these plant tissues helps clarify why xylem is the answer pertaining specifically to water transport.