Transport in Plants

Transport in Plants

Introduction to Transport Systems

• Plants require efficient systems for moving water and nutrients.
• Comparison with human circulatory system, which includes various veins and arteries.

Key Plant Organs and Tissues

• Primary organs: roots, stems, leaves.
• Composed of distinct tissues:
  • Dermal (epidermis)
  • Ground (cortex, pith, mesophyll)
  • Vascular (xylem, phloem, vascular cambium)

Water Transport

• Water is absorbed by roots and transported upwards to leaves via xylem.
• Xylem is composed of tracheids and vessel elements, which are hollow cells.

Water Uptake

• Water enters roots through osmosis via epidermal tissue and root hairs.
• Root hairs enhance surface area for water absorption.

Xylem Sap

• A mixture of water and minerals known as xylem sap accumulates in roots and travels to leaves through veins.

Root Pressure

• Active transport of minerals into xylem increases osmotic pressure, pushing water upwards.

Transpiration Process

• Water is pulled up through cohesion and adhesion to xylem walls due to transpiration from leaves.

Sugar Transport

• Sugars produced during photosynthesis are transported via phloem.
• Phloem is made of living cells (sieve tubes and companion cells) that form continuous tubes for nutrient transfer.

Summary of Transport Mechanisms

• Xylem:
  • Transports water and minerals.
  • Composed of dead cells.
  • Found in roots, stems, leaves.
• Phloem:
  • Transports sugars (phloem sap).
  • Composed of living cells.
  • Active and passive transport mechanisms involved in nutrient distribution.