transpiration and translocation

• describe the structure of xylem tissue

  made of dead cells

  dead cells are joined end to end

  no end walls

  a hole down the middle

  hollow

  contain lingin

  do not have pores as they have no end walls

  tubular
• describe the structure of phloem tissue


  made of living cells

  have pores in their end walls

  have end walls

  tubular

  contains cytoplasm

  doesnt contain lingin
• why do phloem have small pores in their end walls

  to allow cell sap to flow through
• what is cell sap?


  a liquid thats made up of the substances being transported and water
• where does transpiration occur ?

  xylem
• where does translocation occur?

  phloem
• what does the xylem transport?

  water and mineral ions
• how is water transported into the xylem ?

  the root hair cells take up water from the soil by osmosis
• how are the mineral ions transported into the xylem?

  the root hair cells from the soil take up the mineral ions by active transport
• describe what happens in the process of transpiration

  1. the plant loses water due to water vapour diffusing out of the stomata in the plant to use for photosynthesis
  2. xylem tubes carry water and mineral ions up the plant to replace water loss
  3. the xylem does this from the roots to the stem and leaves
  4. the movement of water goes from the roots, through the xylem and out of the leaves (the transpiration stream)
  5. water then evaporates or diffuses out of the leaves
• what does the phloem transport ?

  dissolved sugars
• describe the process of translocation

  1. translocation is the process of transporting dissolved sugars produced by photosynthesis
  2. phloem tissue transports dissolved sugar made in the leaves to the rest of the plant
  3. the plant uses the sugars for immediate use such as growth or storage in the plant
• what direction can translocation flow

  both directions - bi-directional
• what direction can transpiration flow?

  one direction - unidirectional
• overall, what is the point of both of both the phloem and the xylem?

  the xylem and the phloem form a network of vascular bundles, which deliver the water, dissolves sugars, mineral ions and nutrients around the plant and take away the glucose used by photosynthesis