✧˖°transpiration + translocation✧˖°

• What do phloem tubes do?

  Transport nutrients (mainly dissolved sugars) made in the leaves to the rest of the plant for immediate use or for storage.
• Describe the structure of the phloem.


  -made of columns of elongated living cells with small pores in the end walls to allow cell sap to flow through.
• What way does the transport go in a phloem tube?

  both directions
• What is translocation in plants?

  Movement of sugars through phloem.
• What do xylem tubes do?

  Transport water, nutrients & mineral ions from the roots, to the stem and leaves.
• What are xylem tubes made of?

  made of dead cells joined end to end with NO end walls between them and a hole down the middle. They're strengthened with lignin.
• What is lignin?


  Complex polymer found in plant cell walls.
• What is the rate of transpiration affected by?

  Rate of transpiration is affected by factors such as humidity, temperature, wind speed, and light intensity.
• How does light intensity affect transpiration?

  the brighter the light, the greater the transpiration rate.
• How does the stomata get affected by light intensity?

  Stomata begins to close as it gets darker. Photosynthesis cannot take place in the dark, so they dont need to open to let C02 in.
• What happens when the stomata is closed?

  Reduced gas exchange. Very little water can escape.
• How does temperature affect transpiration?

  the warmer it is, the faster transpiration happens. When it is warm, the water particles have more energy to evaporate and diffuse out of the stomata.
• How does air flow affect transpiration?

  the better the air flow around a leaf, the greater of the transpiration rate.
• What happens if air flow around a leaf is poor?

  the water vapour just surrounds the leaf and does not move away. This means there is a high concentration of water particles outside the leaf as well as inside it, so diffusion does not happen quickly.
• What happens if there is good air flow around the plant?

  the water vapour is swept away, maintaining a low concentration of water in the air outside the leaf. Diffusion then happens quickly, from an area of higher concentration to an area of lower concentration.
• How does humidity affect transpiration?

  the drier the air around a leaf, the faster transpiration happens
• What are guard cells adapted to do?

  To open and close the stomata in a leaf.
• What do the guard cells do when the plant has lots of water?

  the guard cells fill with the water, go plump and turgid. This makes the stomata open so gases can be exchanged for photosynthesis.
• What happens to guard cells when the plant is short of water?

  the guard cells lose water and become flaccid, making the stomata close. This helps stop too much water vapour escaping.
• What is a turgid cell?

  A turgid cell is a plant cell that is swollen and firm due to the absorption of water.
• What is a flaccid cell?

  a plant cell that has lost water and has become soft and floppy. It loses its turgidity.
• How does the opening and closing work in guard cells?

  thin outer walls and thickened inner walls make the opening and closing work.
• What are guard cells sensitive to?

  light. They close at night to save water without losing out on photosynthesis.