Plant adaptations

• What are the two main environments discussed in plant adaptations?


  Hot and cold environments
• What are the main strategies plants use to adapt to hot environments?


  • Decrease heat intake
  • Maximise water uptake
  • Minimise water loss
• What is one structural adaptation plants have to decrease heat absorption?


  Light coloured or reflective leaves
• How do plants minimize their surface area exposed to the sun?


  By orienting their leaves vertically
• Why do desert plants have deep root systems?


  To reach groundwater reserves
• How do some plants store water for use in dry seasons?


  By collecting and storing water during the rainy season
• What is the role of guard cells in plants?


  To regulate the opening and closing of stomata
• What happens to guard cells during the hottest parts of the day?


  They lose water and become flaccid, closing the stomata
• What are the structural and physiological adaptations of plants to cold environments?

  • Modifications to the cell membrane
  • Increasing solute concentration (freezing point depression)
  • Seed dormancy
  • Antifreeze proteins
• Why is freezing a problem for alpine and cold-adapted plants?


  It can rupture cell membranes and block nutrient transport
• What happens to cell membrane fluidity at low temperatures?


  It decreases
• How do plants increase their resistance to freezing temperatures?

  By increasing the concentration of solutes in their cells
• What is the function of antifreeze proteins in cold-adapted plants?


  To disrupt the formation of ice crystals within the cell
• What are the advantages of deciduous trees compared to evergreen trees?


  • Avoid frozen leaf tissue during winter
  • Require less energy and water in winter
  • Experience less branch breakage during heavy snowfall
• What is seed dormancy?


  A state where seeds cannot germinate under certain conditions
• When do dormant seeds typically germinate?


  When they detect increases in temperature or light availability
• What is the primary cause of tree lines in cold environments?


  Low temperatures
• What role does precipitation play in the adaptation of plants to cold environments?


  It can influence the location of tree lines
• How do the adaptations of plants in hot environments differ from those in cold environments?


  Hot environment adaptations focus on water conservation, while cold adaptations focus on preventing freezing