Plant Transport Systems: Xylem and Water Movement
Your plant's vascular bundle contains two crucial transport systems working side by side. Xylem vessels are like long, uninterrupted tubes with no end walls - perfect for moving water and minerals from roots to leaves without any blockages.
The water transport process relies on transpiration - when water evaporates from leaves, it creates tension that pulls more water up through the plant. Think of it like a straw effect, but the cohesion between water molecules means they stick together and move as one continuous column.
Several factors speed up transpiration rates. Higher temperatures give water molecules more energy to evaporate faster, whilst lower humidity creates a bigger concentration gradient. Light makes stomata open wider, and wind blows water vapour away, maintaining that crucial concentration gradient.
Quick Tip: Remember the four-step process: evaporation → tension → cohesion → water enters through roots. This sequence is a favourite exam question!
