Plant cell organisation

• 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 a leaf in a plant?


  The leaf is an organ that functions in the transport of substances around the plant.
• What are the main components that form an organ system in plants?


  Leaves, stems, and roots.
• What is the primary function of leaves in relation to photosynthesis?


  Leaves are the site of photosynthesis, requiring carbon dioxide and water to make sugars.
• Where does the water used in photosynthesis come from?


  Water comes from the soil and 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 small holes called stomata.
• What are stomata?


  Stomata are small holes on the leaf that allow carbon dioxide to enter.
• Where are stomata primarily located on a leaf?


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


  Spongy mesophyll tissue has air gaps that allow gas to diffuse easily through the leaf.
• Where does most photosynthesis occur in the leaf?


  Most photosynthesis occurs in the palisade mesophyll layer.
• What are chloroplasts and where are they found in the leaf?


  Chloroplasts are organelles packed in palisade cells where photosynthesis occurs.
• What is the function of phloem in a plant?


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

  The leaf has a waxy cuticle and regulates stomata openings to minimize water loss.
• What is the role of guard cells in relation to stomata?


  Guard cells control the opening and closing of stomata to regulate gas exchange and water loss.
• What happens to guard cells when the plant has plenty of water?


  Guard cells become turgid, making the gap larger for more carbon dioxide to diffuse through.
• What occurs to guard cells when the plant is short of water?


  Guard cells lose water and become flaccid, closing the stomata to conserve water vapor.
• Why do most stomata exist on the underside of leaves?


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


  Meristem tissue is the plant form of stem cells found at the growing tips of roots and shoots.
• What can meristem tissue differentiate into?


  Meristem tissue can differentiate into various cell types for plant growth.
• What are the key functions of leaves in plants?

  • Site of photosynthesis
  • Absorption of carbon dioxide
  • Transport of sugars via phloem
  • Regulation of water loss through stomata
• How do guard cells and stomata work together to balance gas exchange and water loss?


  • Guard cells control stomata openings
  • Open stomata allow carbon dioxide in and water out
  • Turgid guard cells open stomata when water is abundant
  • Flaccid guard cells close stomata when water is scarce
• What adaptations do leaves have to minimize water loss?


  • Waxy cuticle on the upper surface
  • Stomata primarily on the underside
  • Guard cells regulate stomata openings
• What is the relationship between xylem and phloem in a leaf?


  • Xylem transports water to the leaf
  • Phloem transports sugars away from the leaf
  • Both are essential for the leaf's function in photosynthesis and nutrient transport