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 referred to in the study material?

  A cross-section of a leaf
• 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 the roots and xylem
• How does carbon dioxide enter the leaf?

  Through stomata from the outside air
• What are stomata?

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

  On the lower epidermis
• What is the spongy mesophyll tissue's role in the leaf?

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

  In the palisade mesophyll layer
• What do palisade cells contain that is crucial for photosynthesis?

  Chloroplasts
• Why are the upper epidermis cells almost transparent?

  To allow sunlight to pass through
• How are sugars transported in the plant after photosynthesis?

  By the phloem
• What is the main problem leaves face regarding water?

  Water loss
• How does the xylem contribute to leaf function?

  Brings water up from the roots
• What is the purpose of the waxy cuticle on leaves?

  To prevent water loss
• How do stomata affect water loss?

  They allow water to diffuse out
• What happens to stomata when the plant has plenty of water?

  They open wider for gas exchange
• What occurs to guard cells when the plant is short of water?

  They become flaccid and close stomata
• Why do guard cells close at night?

  To conserve water when photosynthesis isn't occurring
• 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 can meristem tissue differentiate into?

  Different cell types for plant growth
• What are the key functions of leaves in plants?

  • Photosynthesis
  • Gas exchange (CO2 in, O2 out)
  • Water regulation
• What adaptations do leaves have to balance gas exchange and water loss?

  • Stomata open and close based on water availability
  • Waxy cuticle prevents excessive water loss
  • Stomata primarily on the underside for shade
• 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
• What is the process of photosynthesis in simple terms?

  • Conversion of CO2 and water into sugars
  • Requires sunlight and chlorophyll
• What is the significance of chloroplasts in palisade cells?

  • Site of photosynthesis
  • Contain chlorophyll for light absorption
• How do guard cells regulate stomata?

  • Turgid guard cells open stomata
  • Flaccid guard cells close stomata
• What is the importance of the cuticle on leaves?

  • Protects against water loss
  • Provides a barrier to pathogens
• What is the role of meristem tissue in plant growth?

  • Allows for differentiation into various cell types
  • Found at tips of roots and shoots