B2.12 Plant transport systems

• What is the process of transporting sugars in plants called?

  Translocation
• How do plants transport water?

  Through transpiration
• Where does photosynthesis occur in plants?

  In the leaves
• What are phloem cells primarily responsible for?

  Transporting sugars
• How are phloem cells arranged?

  End to end to form phloem tubes
• What do the small pores between phloem cells allow for?

  Movement of cell sap
• What is cell sap made of?

  A liquid mixture of water and sugar
• What can sugars be used for once transported?

  For energy or stored for later
• In which directions can phloem transport substances?

  Up or down the plant
• What are xylem tubes made of?

  Dead xylem cells with no ends
• What is the role of xylem tubes?

  Transporting water and mineral ions
• What strengthens xylem tubes?

  Lignin
• What drives the movement of water through a plant?

  Evaporation of water from leaves
• What is transpiration?

  Evaporation of water from leaves
• What is the transpiration stream?

  The chain of water molecules moving up
• What factors influence the rate of transpiration?

  Light intensity, temperature, airflow, humidity
• How does light intensity affect transpiration?

  Higher light increases photosynthesis and transpiration
• What happens to transpiration at nighttime?

  It decreases due to closed stomata
• How does temperature affect the rate of transpiration?

  Higher temperature increases evaporation rate
• What happens to the concentration gradient inside the leaf?

  It allows water to diffuse out of the leaf
• How does high airflow affect transpiration?

  It increases transpiration by blowing away water
• How does humidity affect the rate of transpiration?

  Higher humidity decreases the concentration gradient
• What happens in humid air regarding transpiration?

  Less water diffuses out, reducing evaporation