Adaptations

• What are the three classifications of plants based on water availability?

  Hydrophytes, xerophytes, mesophytes
• What are the characteristics of hydrophytes?

  • Water plants
  • Grow submerged or partially submerged
  • Example: waterlily
• What are the characteristics of xerophytes?

  • Live in water-scarce conditions
  • Highly specialized adaptations
  • Examples: Ammophila, cacti, pine trees
• What are the characteristics of mesophytes?

  • Flourish in adequate water supply
  • Most temperate region plants
  • Most crops are mesophytes
• How do mesophytes reduce water loss at night?


  They close stomata to decrease water loss
• How do mesophytes survive winter conditions?

  They shed leaves and have underground organs
• What is the scientific name for the waterlily?

  Nymphea
• Why does the waterlily have little or no waxy cuticle?

  Water loss is not a problem for them
• Where are the stomata located on the waterlily?

  On the upper surface of the leaf
• Why is xylem poorly developed in hydrophytes?

  Little need for highly developed transport tissues
• What role do large air spaces in hydrophytes serve?

  They form reservoirs of oxygen and carbon dioxide
• Why is lignified support tissue not needed in waterlilies?

  Water is a support medium for the plant
• How do rolled leaves in Ammophila help reduce water loss?

  They reduce the leaf area exposed to air
• What is the function of the thick waxy cuticle in xerophytes?

  It reduces water loss by evaporation
• How do stiff hairs on xerophytes help with water retention?

  They trap water vapor and reduce gradient
• What is the role of sunken stomata in xerophytes?

  They allow water vapor to accumulate above pores
• How do sunken stomata reduce transpiration in xerophytes?

  They increase humidity in the air chamber
• What effect does leaf rolling have on transpiration in xerophytes?

  It reduces the rate of transpiration