Application questions

• How is K+ mainly transported in the xylem?

  K+ is mainly transported upwards
• How does K+ move into the xylem from the phloem?

  K+ only moves laterally into the xylem
• What does waxed paper demonstrate in the context of movement?

  Waxed paper stops movement of substances
• What happens to the values if separated by waxed paper?

  Values would be the same at all points
• What is the transport direction in the xylem and phloem?

  No/little transport in xylem, both directions in phloem
• What should be analyzed to determine movement in both directions?

  Samples from above and below the leaf
• What indicates that movement is occurring in both directions?

  If both samples are positive
• What happens to sucrose during summer in leaves?

  Sucrose is loaded into the phloem
• What effect does sucrose loading have on water potential?

  Water potential falls as water moves in
• What causes an increase in hydrostatic pressure in the phloem?

  Water potential falls, causing hydrostatic pressure increase
• What do tubers do with sucrose?

  Tubers convert sucrose into starch
• What happens to water potential in tubers after converting sucrose?

  Water potential rises as they lose water