Transpiration,translocation and stomata

• What are phloem tubes made of?


  Columns of elongated living cells with small pores
• What do phloem tubes transport?


  Food substances, mainly dissolved sugar
• In which direction do phloem tubes transport substances?


  In both directions
• What is the process called when phloem tubes transport food?

  Translocation
• What are xylem tubes made of?


  Dead cells joined end to end with no end walls
• What do xylem tubes carry?


  Water and mineral ions from the roots to the stem and leaves
• What is the transpiration stream?


  The movement of water from the roots, through the stem and out of the leaves
• What causes transpiration?


  The evaporation and diffusion of water from a plant’s surface
• Where does most transpiration occur in a plant?


  At the leaves
• What happens when water evaporates from the leaves?


  A slight shortage of water is created in the leaf
• What is the effect of the shortage of water in the leaf?

  More water is drawn up from the rest of the plant through the xylem vessels
• What does the constant transpiration stream indicate?


  There is a continuous movement of water through the plant
• Why is transpiration considered a side effect of leaf adaptation?


  Because leaves are adapted for photosynthesis, which requires gas exchange
• What do leaves have that allows for gas exchange?

  Stomata
• How does water escape from the leaves?

  Through the stomata by diffusion
• Why does water escape from the leaves?


  Because there is more water inside the plant than in the air outside
• What are the main functions of phloem and xylem in plants?


  • Phloem: Transports food substances (mainly dissolved sugar) in both directions.
  • Xylem: Carries water and mineral ions from the roots to the stem and leaves.
• What is the relationship between transpiration and photosynthesis in plants?


  • Transpiration is a side effect of leaf adaptation for photosynthesis.
  • Stomata allow gas exchange, leading to water loss through evaporation.
• What are the two main types of vascular tissue in plants?

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


  To carry water and mineral ions from the roots
• What are xylem tubes made of?


  Dead cells
• Why do xylem cells have lignin?


  For strength
• What does the transpiration stream refer to in xylem tissue?


  The movement of water in the xylem
• What type of cells make up phloem tissue?


  Elongated living cells
• What is the function of small pores in the end walls of phloem cells?


  To let cell sap through
• What substances are primarily moved through phloem from leaves?


  Food substances, mainly dissolved sugars
• What happens to food molecules transported through phloem?


  They can either be used immediately or stored
• What is translocation in the context of phloem tubes?


  The process in which food is moved through phloem tubes
• What are the key differences between xylem and phloem?

  • Xylem:
  • Carries water and minerals
  • Made of dead cells
  • Contains lignin for strength
  • Phloem:
  • Transports food substances
  • Made of living elongated cells
  • Has small pores for cell sap movement
• What is transpiration in plants?


  Transpiration is the loss of water from a plant.
• How do substances move in plants?

  Substances move through the plant via transpiration and translocation.
• What is the role of phloem in plants?


  Phloem transports sugars made in leaves.
• What happens to sugars produced in leaves?


  Sugars can be directly used for energy or stored.
• How does the liquid nature of water support plant movement?


  The liquid nature of water allows for the movement of substances through cells.
• How is sugar transported over long distances in plants?


  Sugar made in leaves can be transported through multiple cells.
• What is the function of xylem in plants?


  Xylem transports water and minerals from roots.
• What are dead xylem cells and their structure?


  Dead xylem cells form long hollow tubes with no ends between them.
• What is the role of lignin in xylem cells?


  Lignin provides strength to the xylem cells.
• How does evaporation affect transpiration?


  Water evaporates and diffuses out of the plant, causing more water to be drawn in from the roots.
• What is the transpiration system in plants?


  The transpiration system is a chain of water molecules moving through the plant.