Transport in plants

• WHAT DOES XYLEM TRANSPORT?

  Water and minerals
• WHAT DOES PHOLEM TRANSPORT?

  sugars like sucrose
• DESCRIBE POSITION OF XYLEM AND PHOLEM IN LEAF

  mark both xylem and phloem?

  A)

  B)

  
• MARK XYLEM AND PHLOEM IN THE STEM

  mark

  A)

  B)

  C)

  
• WHY IS IT PLACED LIKE THAT IN THE STEM?

  they are arranged in bundles near the edge to resist compression and bending forces
• MARK THE POSITION OF XYLEMA ND PHLOEM IN THE ROOTS

  mark all the empty boxes

  A)

  B)

  C)

  D)

  E)

  
• WHAT IS THE PATHWAY OF WATER IN A PLANT?

  1. root hair cell
  2. root cortex
  3. xylem
  4. mesophyll cell
• HOW ARE ROOT HAIR CELLS ADAPTED TO THEIR FUNCTION?

  • long root hair to increase surface are therefore absorption is higher
  • thin membranes to decrease diffusion distance
  • many mitocondria to provide energy for active transport
  • carrier proteins on either side of the cell to allow minerals to enter.
• DEFINE TRANSPIRATION

  the evaporation of water from the aerial parts of a plant on the surface of mesophyll cells along with diffusion of water vapor through the stoma
• DESCRIBE THE PROCESS OF TRANSPIRATION

  1. water lost through stoma
  2. more water pulled up to replace lost water
• EXPLAIN MOVEMENT OF WATER IN PLANTS

  water evaporates creating negative pressure in the xylem( transpiration pull)

  water molecules drawn up the xylem and held together through cohesion
• WHAT IS COHESION AND ADHESION?

  cohesion is that water molecules tend to attract each other sticking together due to hydrogen bonds

  adhesion is that water molecules tend to stick to the inside of xylem vessels
• HOW DOES TEMPERATURE AFFECT TRANSPIRATION?

  as temperature increases ,transpiration increase and molecules gain more kinetic energy and evaporation occurs faster
• HOW DOES LIGHT INTENSITY AFFECT TRANSPIRATION?

  rate of transpiration increase as more photosynthesis occurs and the stoma are open which allows more water vapor to escape
• HOW DOES WIND SPEED AFFECT TRANSPIRATION ?

  faster wind speed allows water to be carried away faster which makes a steeper gradient and increases transpiration rate
• WHY DO PLANTS WILT?

  lack of water which means plant cells are not turgid and are not supported
• WHAT IS TRANSLOCATION?

  Movement of sugars and amino acid from source to sink
• ADAPTATIONS OF XYLEM

  • Cells joined end to end with no cross walls to form a long continuous tube
  • Cells are essentially dead, without cell contents, to allow free passage of water
  • Outer walls are thickened with a substance called lignin, strengthening the tubes, which helps support the plant
• FUNCTION OF STOMA

  • diffusion of gases in and out of plant
  • diffusion of water vapor out of plant
• WHY IS TRANSPIRATION IMPORTANT?

  It helps keep the leaves cool 

  maintain cell turgidity

  Transport of dissolved minerals
• EQUIPMENT USED TO MEASURE TRANSPIRATION

  potometer
• ADVANTAGES OF WILTING

  • (Wilting causes) the stomata to close
  • This helps to prevent more water loss
  • Therefore water is conserved for other processes
  • (Wilting leads to) a decrease surface area exposed to the Sun