Leaf Structure

• What are the different levels of organization in plants?

  Cells, tissues, organs, organ systems
• What is the function of the organ system formed by leaves, stems, and roots?

  Transport of substances around the plant
• What is the structure of a leaf described as?

  A cross-section sliced from top to bottom
• What is the primary function of leaves?

  Photosynthesis
• What do leaves require for photosynthesis?

  Carbon dioxide and water
• How is water transported to the leaves?

  By roots and xylem
• How does carbon dioxide enter the leaf?

  Through stomata from outside air
• What are stomata?

  Little holes for gas exchange
• Where are stomata primarily located on the leaf?

  Lower epidermis
• What is the role of spongy mesophyll tissue?

  Facilitates gas diffusion
• Where does most photosynthesis occur in the leaf?

  In the palisade mesophyll layer
• What do palisade cells contain that aids photosynthesis?

  Chloroplasts
• Why are the upper epidermis cells almost transparent?

  To allow sunlight to pass through
• What transports sugars produced in photosynthesis?

  Phloem
• What is the main problem leaves face?

  Water loss
• How does the waxy cuticle help the leaf?

  Prevents water loss
• What happens to stomata during water shortage?

  They close to conserve water
• What are guard cells responsible for?

  Regulating the opening and closing of stomata
• What happens to guard cells when the plant has plenty of water?

  They become turgid and open stomata
• Why are most stomata located on the underside of leaves?

  To reduce water evaporation
• What is meristem tissue in plants?

  Plant form of stem cells
• Where is meristem tissue found?

  At the growing tips of roots and shoots
• What is the process of photosynthesis in leaves?

  • Absorption of sunlight by chlorophyll
  • Carbon dioxide enters through stomata
  • Water is absorbed from the soil
  • Glucose is produced as a sugar
  • Oxygen is released as a byproduct
• What adaptations do leaves have to balance gas exchange and water loss?

  • Stomata open and close via guard cells
  • Waxy cuticle prevents water loss
  • Stomata primarily on the underside for shade
  • Guard cells respond to water availability and light
• What are the main tissues found in a leaf and their functions?

  • Upper epidermis: Protects and allows light entry
  • Palisade mesophyll: Main site of photosynthesis
  • Spongy mesophyll: Facilitates gas diffusion
  • Lower epidermis: Contains stomata for gas exchange
• What is the role of xylem and phloem in plants?

  • Xylem: Transports water from roots to leaves
  • Phloem: Transports sugars from leaves to other parts