PLANT STRUCTURES AND THEIR FUNCTIONS

• What is gas exchange?

  Gas exchange is the process by which organisms exchange gases with their environment.
• What gases are primarily exchanged in plants during gas exchange?

  Carbon dioxide (CO2) and oxygen (O2).
• Why is gas exchange crucial for plants?

  It is essential for photosynthesis and respiration.
• What are the key points of gas exchange in plants?

  • Involves exchange of CO2 and O2
  • Occurs between plant and atmosphere
  • Essential for photosynthesis and respiration
• What is the role of CO2 in photosynthesis?

  CO2 is taken in by plants to produce glucose and oxygen.
• What is the role of O2 in cellular respiration?

  O2 is used to break down glucose for energy.
• What are the critical processes supported by gas exchange in plants?

  1. Photosynthesis: Provides CO2
  2. Cellular respiration: Provides O2
  3. Maintains gas balance in plant tissues
  4. Essential for plant growth and survival
• What is the primary site of gas exchange in most plants?

  Leaves.
• What is the function of the epidermis in leaves?

  The epidermis serves as an outer layer of cells that prevents water loss.
• What are stomata and their role in gas exchange?

  Stomata are small pores that allow gases to enter and exit the leaf.
• What is mesophyll and its role in gas exchange?

  Mesophyll is the inner leaf tissue that facilitates gas diffusion.
• What are vascular bundles in leaves?

  Vascular bundles contain xylem and phloem for water and nutrient transport.
• What are the key adaptations of leaves for gas exchange?

  • Large surface area to volume ratio
  • Thin leaves for short diffusion distances
  • Numerous stomata for gas exchange
• What initiates gas exchange through stomata?

  Stomatal opening occurs when guard cells change shape.
• How does CO2 enter the leaf during gas exchange?

  CO2 diffuses into the leaf through open stomata.
• What happens to O2 produced during photosynthesis?

  O2 diffuses out of the leaf through stomata.
• What drives the movement of gases during gas exchange?

  Diffusion drives gas movement from high to low concentration.
• What role do guard cells play in gas exchange?

  Guard cells control the opening and closing of stomata.
• What factors affect gas exchange in plants?

  1. Light intensity
  2. Temperature
  3. Humidity
  4. CO2 concentration
  5. Water availability
  6. Wind
  7. Plant hormones
• How does light intensity affect gas exchange in plants?

  Higher light levels generally increase stomatal opening and gas exchange.
• What effect does temperature have on gas exchange?

  Temperature affects the rate of photosynthesis and respiration, influencing gas exchange needs.
• How does humidity influence gas exchange?

  Low humidity increases transpiration, potentially leading to stomatal closure.
• What happens to gas exchange when a plant experiences water stress?

  Stomata close to conserve water, reducing gas exchange.
• How does wind affect gas exchange in plants?

  Wind can increase gas exchange by reducing the boundary layer around leaves.
• What role do plant hormones play in gas exchange?

  Plant hormones, such as abscisic acid, can trigger stomatal closure.
• How do plants balance gas exchange with water conservation?

  • Stomata open for gas exchange
  • Stomata close to conserve water
  • Adaptations help optimize gas exchange in different environments