the uptake of water and mineral ions by the root

• What is the casparian strip?


  A waxy layer on endodermis cells of the root which forces water and minerals to enter the endodermal cells.
• what happens to the the endodermis water and mineral ions whilst moving though the apoplast pathway


  it is forced into the symplast pathway
• why is the endodermis water moved into the symplast pathway from the apoplast pathway


  this is due to the casparian strip found in the cell walls of endodermal cells
• what is the Casparian strip made of?


  suberin
• what is a feature of the caspairian stip being made out of suberin


  it is impermeable meaning that hte apop pathway is blocked
• how do the mineral ions and water enter teh xylem from the endodermis


  mineral ions are actively transported from ouside the endodermal cells into the cytoplasm and they then diffuse from there to the pericycle and into the xylem
• list the layers in which water moves in by osmosis


  epidermis ,cortec endodoermis and pericycle
• why do plants need to control entry of mineral ions into the xylem


  some mineral ions are toxic if they are absorbed
• how do plants ensure toxic ions cannot enter its cells


  the membranes are impermeable withount proteins as ions are charged
• why do plants need to absorb nitrates from the soil


  required for the synthesis of nucleotides such as atp dna and rna
• what is the use of potassium ions in plants


  for the opening and closing of the stomata`
• what is the use of magnesium ions in plants


  it is a constitute for chlorophyll
• what is an example of mineral ions

  nitrates
• how are mineral ion s transported into the plant


  by active transport in the roots
• what happens to the water potential inside the cell when water moves in by osmosis


  it will lower
• what are the three types of pathways to transport water around the plants

  symplast apoplast and vacuolar
• what is the definiton of the apoplast pathway


  water is taken up by the root hair cell and moves across the cortex by cohesion via cell walls
• what is the definition of the symplast pathway


  water moves from the cytoplasm of one cell to teh next by osmosis via the plasmodestmata
• what is the plasmodesmata


  channels through cell walls that connect the cytoplasms of adjacent cells
• what is the defintion of the vacuolar pathway


  water moves via cytoplasm and vacuoles