Transpiration

• What is transpiration in plants?

  Transpiration is the process of water evaporating from the surfaces of leaves.
• What are the key roles of transpiration in plants?

  • Brings water to the leaf for photosynthesis
  • Transports dissolved mineral ions
  • Cools the leaf during warm weather
• What tissues are key in the leaf for transpiration?

  Palisade mesophyll and xylem.
• How does water enter the roots of a plant?

  Through root hair cells.
• What is the transpiration stream?

  It is the movement of water from the roots to the leaves.
• What is the first step in the process of transpiration?

  Evaporation of water from cells inside the leaf.
• What happens to water vapor after it evaporates from the leaf?

  It diffuses through air spaces and exits through the stomata.
• What factors affect the rate of transpiration in plants?

  • Higher temperatures increase the rate
  • Dry conditions increase the rate
  • Windy conditions increase the rate
  • Higher light intensity increases the rate
• Why does transpiration increase in windy conditions?

  Because wind removes water vapor, allowing more evaporation.
• How does light intensity affect transpiration?

  It increases the rate because stomata open for photosynthesis.
• What are stomata and their function in plants?

  • Stomata are openings on the leaf surface
  • Allow gas exchange (CO2 in, O2 out)
  • Facilitate water vapor loss during transpiration
• What role do guard cells play in the function of stomata?

  They regulate the opening and closing of stomata.
• What happens to guard cells during high light intensity?

  They swell and open the stomata.
• Why do plants close their stomata under hot conditions?

  To reduce water loss by transpiration.