Plant Transport System
Your body has blood vessels, and plants have something similar called vascular bundles. These are like plant highways that carry essential materials around. In leaves, they form a network that supports the soft tissue and helps the leaf stay strong. In stems, they're positioned around the outer edge to give the plant structural support.
Xylem is the plant's water delivery system - think of it as one-way plumbing. It's made from dead cells that have lost their end walls, creating continuous tubes. These tubes have thick walls strengthened with lignin (a tough material) and are completely waterproof. Water and minerals flow upward from roots to leaves, and there's no going back.
Phloem is much more flexible than xylem. It's made of living cells that transport dissolved sugars created during photosynthesis. Unlike xylem's one-way system, phloem allows two-way flow - sugars can move up to growing tips or down to roots for storage. The cells have special sieve plates with tiny holes that let sugar solutions pass through.
Quick Tip: Remember it this way - Xylem carries water up (both start with vowels), whilst phloem is flexible and carries food both ways!
The positioning of vascular bundles is clever too. In roots, they're in the centre so roots can bend when the plant sways in wind without snapping. This arrangement helps anchor the plant whilst maintaining flexibility.