Structure and function

• What are the two main types of plant tissues for transport?

  Xylem and phloem
• What is the primary function of xylem in plants?

  To transport water and minerals upward
• What type of cells make up phloem tissue?

  Living cells
• What is the significance of xylem being dead at maturity?

  It maximizes space for water transport
• What process begins the movement of water in xylem vessels?

  Transpiration from leaves
• What is the key difference in the cell walls between xylem and phloem?

  Xylem cells have no end walls between them, while phloem cells have perforations in their end walls
• What type of cells make up xylem tissue?

  Dead cells
• Why do xylem cells have thick walls stiffened with lignin?

  To provide structural support and allow for the transport of water and minerals
• In which direction does xylem transport substances?

  Upward
• What are the two main products of photosynthesis?

  • Photosynthesis products (phloem)
  • Water and minerals (xylem)
• What are the structural differences between xylem and phloem?

  • Cell walls:
  • Xylem: Thick, lignin-reinforced
  • Phloem: Thin, cellulose
  • Flow direction:
  • Xylem: One-way (up)
  • Phloem: Two-way
  • Cell connections:
  • Xylem: Continuous channels
  • Phloem: Perforated end walls
  • Cell type:
  • Xylem: Dead at maturity
  • Phloem: Living cells with cytoplasm
• How do the functions of the phloem and xylem differ in terms of the substances they transport?

  Phloem transports organic compounds, xylem transports water and minerals
• How do the structural features of xylem support its function?

  Thick walls allow efficient water transport upward
• What is the role of the phloem and xylem in a plant?

  • Phloem transports photosynthesis products
  • Xylem transports water and minerals
• What is the primary function of phloem in plants?

  Transporting sugars in multiple directions
• What happens to water after sugars are unloaded in phloem?

  It returns to xylem for recirculation
• How do the photosynthesis products and water/minerals move through the plant?

  • Photosynthesis products move through the phloem
  • Water and minerals move through the xylem
• What theory explains how water is transported through xylem vessels?

  Cohesion-tension theory
• What is the role of xylem in plants?

  Transporting water and minerals
• What type of cells load sucrose into phloem?

  Source cells
• What are the differences between xylem and phloem?

  • Xylem:
  • Carries: Water and minerals
  • Direction: Upward
  • Structure: Dead cells
  • Phloem:
  • Carries: Sugars
  • Direction: Both directions
  • Structure: Living cells
• What property of water allows molecules to stick together in xylem?

  Cohesion
• What role does lignin play in xylem structure?

  Lignin reinforces cell walls for strength
• What is the main difference between xylem and phloem?

  Xylem transports water and minerals, while phloem transports water and food
• What are the two types of vascular tissue in plants?

  Xylem and phloem
• How does transpiration pull water up through the xylem vessels?

  Transpiration pulls water up through the xylem vessels by creating a suction force
• Where are sugars unloaded in the phloem transport process?

  At destination cells
• Describe the movement of water in the xylem system.

  • Water evaporates from leaves (transpiration)
  • Tension pulls water upward
  • Cohesion keeps water molecules together
  • Adhesion helps water stick to xylem walls
• How do the sink cells help drive the movement of water through the plant?

  Sink cells unload water from the xylem vessels, creating a pressure potential that drives the sap down the xylem tubes
• Why is the flow direction in phloem two-way?

  It allows for distribution of sugars as needed
• How does phloem function in plants?

  It transports sugars from leaves to other parts
• How does transpiration create tension in the xylem?

  It pulls water upward through the plant
• How are the functions of the phloem and xylem different?

  • Phloem transports organic compounds (photosynthesis products)
  • Xylem transports water and inorganic minerals
• How does water move through the plant?

  • Water is pulled up through the xylem vessels by transpiration
  • Sucrose is loaded into the xylem vessels by source cells, reducing their water potential
  • This water potential difference drives the flow of water up the xylem vessels
  • Water is then unloaded into the sink cells
• What are the main functions of xylem and phloem?

  Xylem:

  • Transports water and minerals from roots to leaves
  • Provides structural support to the plant

  
  

  Phloem:

  • Transports food (glucose) from leaves to other parts of the plant
  • Allows for two-way flow of materials
• How does the absence of the transport system affect plant growth?

  Plants couldn't grow tall or survive droughts
• What are the key processes involved in the movement of water through the plant?

  • Transpiration pulls water up through the xylem vessels
  • Source cells load sucrose into the xylem, reducing their water potential
  • Water potential differences drive the flow of water up the xylem
  • Water is unloaded into sink cells
• How do the structural features of phloem support its function?

  Perforated walls allow sugar movement in multiple directions
• What is the purpose of the source cells in the image?

  Source cells load sucrose into the xylem vessels, reducing their water potential
• What process causes water to move into phloem?

  Osmosis