Structure of a Leaf and Stomata

• What are the different levels of organization in plants?

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


  It functions to transport substances around the plant.
• What is the primary function of leaves?

  Leaves are the site of photosynthesis.
• What do leaves require for photosynthesis?


  Leaves require carbon dioxide and water to make sugars.
• How is water transported to the leaves?


  Water is transported to the leaves by the roots and xylem.
• How does carbon dioxide enter the leaf?


  Carbon dioxide diffuses directly into the leaf through stomata.
• What are stomata?


  Stomata are small holes on the leaf surface that allow gas exchange.
• Where are stomata primarily located on the leaf?


  Stomata are primarily scattered through the lower epidermis of the leaf.
• What is the role of spongy mesophyll tissue in leaves?


  Spongy mesophyll tissue allows gas to easily diffuse through the leaf.
• Where does most photosynthesis occur in the leaf?


  Most photosynthesis occurs in the palisade mesophyll layer.
• What are chloroplasts?


  Chloroplasts are organelles that carry out photosynthesis in plant cells.
• What is the function of phloem in plants?


  Phloem carries sugar molecules to the rest of the plant.
• How does the leaf minimize water loss?


  The leaf has a waxy cuticle that prevents water loss.
• What is the role of guard cells in relation to stomata?


  Guard cells control the opening and closing of stomata.
• What happens to guard cells when the plant has lots of water?


  Guard cells become turgid, making the stomata open wider.
• What occurs to guard cells when the plant is short of water?


  Guard cells lose water and become flaccid, closing the stomata.
• Why do most stomata open during the day and close at night?


  Stomata open during the day for photosynthesis and close at night to conserve water.
• Why are most stomata located on the underside of leaves?


  Most stomata are on the underside to reduce water evaporation due to shading.
• What is meristem tissue in plants?


  Meristem tissue is the plant form of stem cells that can differentiate into various cell types.
• Where is meristem tissue found in plants?


  Meristem tissue is found at the growing tips of roots and shoots.
• What are the key functions of leaves in plants?

  • Site of photosynthesis
  • Absorb carbon dioxide
  • Release oxygen
  • Minimize water loss
• What adaptations do leaves have to balance gas exchange and water loss?

  • Stomata for gas exchange
  • Guard cells regulate stomata opening
  • Waxy cuticle to reduce water loss
  • Spongy mesophyll for gas diffusion
• What is the process of photosynthesis in leaves?


  1. Absorption of sunlight by chlorophyll
  2. Water uptake from roots via xylem
  3. Carbon dioxide intake through stomata
  4. Production of glucose and oxygen