What does the xylem transport? Which direction does it travel? Which substance is the xylem primarily responsible for transporting?
Answer (1)
Xylem is a type of tissue in vascular plants that is responsible for the transport of water and certain dissolved minerals from the roots to the rest of the plant.
The xylem primarily transports water and nutrients absorbed from the soil through the plant. This transport happens in one direction – upwards from the roots up the stem and to the leaves.
Here's how it works step-by-step:
Water Absorption: The roots of a plant absorb water from the soil, where it enters the root hair cells.
Movement in the Xylem: Once inside the plant, water travels through the xylem vessels, which are long tube-like structures. These vessels are made up of dead cells that form a continuous column, allowing efficient movement.
Capillary Action and Transpiration Pull: The movement of water in the xylem is mainly driven by two phenomena:
Capillary Action: The tendency of water to flow in narrow spaces without the assistance of external forces. This is because of cohesion (water molecules sticking to each other) and adhesion (water molecules sticking to the walls of the xylem).
Transpiration Pull: As water evaporates from the leaves (a process known as transpiration), it creates a negative pressure that pulls more water up through the xylem from the roots.
In summary, xylem's primary role is to transport water and dissolved salts from the roots to the rest of the plant, which is crucial for various physiological processes such as photosynthesis and nutrient distribution.
