Transport in plants

• What are trichomes and its function?

  They are the fuzzy hairs that are at the very top of the leaf.

  They prevent insects from crawling over the leaf
• What is the upper epidermis and its function?


  It is a compacted and transparent thin layer of the leaf structure that lets sunlight pass through to be absorbed in palisade and spongy mesophyll
• What is the waxy cuticle and its function?

  It’s underneath the trichomes and it protects the leaf. It is hydrophobic so water won’t be able to diffuse in which means it prevents water loss
• What are leaves?

  Leaves are organs and is the site of photosynthesis
• What are the components of a leaf?

  Trichomes, waxy cuticle, upper epidermis, palisade mesophyll, spongy mesophyll, vascular bundle - phloem, xylem, lower epidermis, stoma/stomata, guard cells, meristem tissues
• What is the stoma and its function?

  It has pores for gas exchange.

  Co2 diffuses in and o2 out
• What is transpiration?

  Transpiration is the process by which plants release water vapor into the atmosphere through their leaves. (evaporation)
• What are the 4 factors that affect transpiration?

  1.Light - The stoma opens wider to let co2 in. The brighter it is, the more it can photosynthesise

  2.Temperature - Particles gain energy when warmer to diffuse easier

  3.Wind/air flow-Depends on the gradient. Concentration will be higher if more wind, it blows away water vapour

  4.Humidity-Higher humidity will decrease the rate of evaporation of water
• What is meristem and where is it found?

  Undifferentiated plant tissue (plant stem cells).

  Found in growing tips and root tips
• What is the xylem and its function?

  Vascular tissue. Transport water and nutrients from roots to plant
• Which substance is reinforced with xylem cells to make them stronger?

  Lignin.

  EXTRA: xylem tubes are dead
• What are the guard cells and its function?

  Guard cells regulate the opening and closing of stomata in plant leaves to control gas exchange and water loss.
• What are the adaptations of guard cells?

  -Guard cells have adaptations such as a kidney-shaped structure, thickened cell walls, and the ability to change shape to regulate the opening and closing of stomata.

  -sensitive to light so it opens for a short while

  -turgid. opens and allows co2 to enter leaf

  -if flaccid, it won’t open and would only open in the day
• What is translocation in plants?

  Movements of cell sap (mixture of water and sugar) up and down the phloem
• What is translocation used for in plants?


  Can be used for energy or can be stored
• What is the lower epidermis and its function?

  It’s located at the bottom and is a thin layer of the leaf that has stomas in between it which prevents water loss
• What is the phloem and its function?

  Vascular tissue that transports sugars and other organic nutrients all throughout the plant
• What is the spongy mesophyll snd its function?

  More loosely pack of cells that contains chloroplasts for photosynthesis and controls gas exchange
• What is the palisade mesophyll and its function?

  Compacted layer of cells in plant leaves that contains some chloroplasts which are responsible for photosynthesis. Also controls gas exchange
• What do phloem cells have that allows cell sap to pass along the phloem tube?

  Pores