Chapter 8 - Plant Transport

• Phloem


  Transports nutrients, amino acids, sucrose
• Phloem

  • Sieve tube element - got cytoplasm, no nucleus
  • Cytoplasm
  • Companion cell - got nucleus
  • Sieve plate
• Xylem

  • Transports H2O
  • Dead cell end of cell walls break down
  • Cell wall contains cellulose and lignin
• Lignin is a hard substance that keep the stem upright
• Xylem

  • Cell wall - cellulose and lignin
  • No nucleus
  • No cytoplasm
• Cohesion and adhesion of H2O molecules that sticks towards xylem will to come upwards
• Transpiration


  Evaporation of water from leaf surface
• Factors affecting transpiration

  • Light
  • Temperature
  • Wind
  • Humidity
  • Water supply
• Root


  • Protects the root as it grows through soil
  • Short life span, replaced by new ones
  • Increases surface area
• Water absorption by root


  1. Osmosis

  2. Across root cells

  3. Seeps between cells

  4. Drawn up xylem by transpiration
• Translocation


  Movement of nutrients from source to sink
• Nutrients translocated


  • Amino acids
  • Sucrose
• Nutrients are made/stored where they are needed
• Evaporation in transpiration is the difference in pressure that creates transpiration pull
• Source is where nutrients are made or stored
• Sink is where nutrients are needed