Plant nutrition

    Cards (24)

    • photosynthesis
      the fundamental process by which plants manufacture carbohydrates from raw materials using energy from light.
    • What 3 Elements do plants need?
      oxygen, carbon and hydrogen
    • cuticle
      Waxy substance secreted by upper epidermal cells to reduce water evaporation from leaf surface.
    • epidermis
      An outer layer of cells that form a transparent protective layer (against fungi and bacteria). *Chloroplasts are absent.
    • stomata
      Pores are present on the lower epidermis.
      Allows diffusion of gases in and out of the leaf including water vapour.
    • guard cells
      Pair of bean-shaped cells that open or close the stoma.
      Contain chloroplasts.
    • palisade layer

      Cells are rectangular and stand on their end. They contain a large number of chloroplasts.
    • spongy layer

      Cells are smaller, rounder and also contain chloroplasts.

      Intercellular air spaces allow air to diffuse to cells inside the leaf.

      Provide a large moist thin surface for gas exchange.
    • xylem
      Transports water and mineral ions from roots to leaves.
      *Always on top of the phloem in the leaf.
    • phloem
      Transports sucrose and amino acids produced from the leaves to other parts of the plant.
    • vascular bundle

      Tubes (vessels) in the outer parts of the stem which contain the xylem and phloem.
    • sucrose
      Transported in the phloem.
    • What are the limiting factors affecting the rate of photosynthesis?
      light intensity
      CO2 concentration
      temperature
      chlorophyll
    • What mineral nutrients do plants need and why?
      Nitrates: contain nitrogen to form amino acids to make proteins. Nitrogen deficency results in stunted growth.

      Magnesium: part of chlorophyll molecule. Results in taller plant but yellow leaves.
    • How do you test for sucrose in a plant?
      Add benedicts solution and it fails to react unlike glucose so its a non-reducing sugar.
    • Why do plants store glucose as starch?
      It is insoluble and has no osmotic effect so it will not diffuse out of leaf cells.
    • What are the differences between phloem and xylem?
      Xylem-carry minerals/H2O, dead, no end walls, passive transport.

      Phloem-carry sucrose, amino acids, alive, active transport.
    • What is sap?
      water, sucrose, amino acids
    • photosynthesis word equation
      carbon dioxide + water = glucose + oxygen
    • How does carbon dioxide enter a plant?
      Through stomata by diffusion and into moist gas exchange surface of the mesophyll cells and diffusion to palisade layer. (Occurs during the day).
    • What is the role of chlorophyll?
      Chlorophyll absorbs light energy and converts it into chemical energy for the formation of carbohydrates.
    • What is the balanced chemical equation for photosynthesis?
      6CO₂ + 6H₂O (light & chlorophyll) → C₆H₁₂O₆ + 6O₂.
    • limiting factor
      something present in the environment in such short supply that it restricts life processes.
    • What are the uses and dangers of nitrogen fertilisers?
      Used to increase plant growth through formation of protein form nitrates.

      Danger is eutrophication of water ways and poisoning of soil drinking water.
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