State the functions of xylem and phloem in transport of water, mineral salts and food.

Transport in Plants 🌱

Objective: State the functions of xylem and phloem in transport of water, mineral salts and food.

Xylem – The Water Highway 🚰

Xylem is a network of vessels that moves water and dissolved minerals from the roots to the rest of the plant.

• Transports water (💧) and mineral salts (🧂).
• Moves from roots to leaves via capillary action, cohesion‑tension, and root pressure.
• Provides structural support because of lignified cell walls.

Phloem – The Food Delivery System 🍎

Phloem carries the sugars (mainly sucrose) and other organic nutrients from photosynthetic sites to non‑photosynthetic tissues.

• Transports sugars, amino acids, hormones, and other metabolites.
• Movement is driven by a pressure‑flow (mass flow) mechanism.
• Can move substances in both directions (source → sink and sink → source).

Key Functions in a Nutshell 🥜

1. Xylem: Water & mineral transport, structural support.
2. Phloem: Food & nutrient transport, signaling.

Analogy: The Plant’s Transport Network 🛣️

Think of the plant as a city:

• Xylem: Highways that carry water and minerals from the “water reservoir” (roots) to every building (tissues).
• Phloem: Delivery trucks that bring food (sugars) from the “factory” (leaves) to the “homes” (roots, stems, flowers).

Comparison Table 📊

Quick Quiz 🎯

1. What is the main material transported by xylem?
2. Which transport system can move substances in both directions?
3. What drives the flow in phloem?

Answers: 1) Water & minerals. 2) Phloem. 3) Pressure‑flow (osmotic pressure).