Plant diseases and defences

Cards (12)

  • What happens if there aren’t enough mineral ions in the soil
    Plants suffer deficiency symptoms
  • why do plants need nitrates
    to make protines
  • what happens if plants don’t have enough nitrates
    proteins are needed for growth so a lack of nitrates causes stunted growth
  • what do plants need magnesium ions for
    making chlorophyll
  • what happens if plants don’t have enough magnesium ions
    they have chlorosis (yellow leaves) and can’t photosynthesise as well
  • what are aphids
    an insect that infests and damages plants
  • what are common signs of a plant disease
    -stunted growth
    -abnormal growth
    -spots on the leaves
    -malformed stems or leaves
    -patches of decay
    -discolouration
  • how can plant diseases be identified
    -looking up signs in a gardening manual or website
    -taking the plant to a laboratory
    -using testing kits that identify the pathogen with monoclonal antibodies
  • what are physical defences
    -waxy cuticle which provides a barrier to stop pathogens entering
    -plant cells have cell walls which form another physical barrier
    -layers of dead cells around the stems that acts as a barrier
  • what are chemical defences
    -some plants produce antibacterial chemicals to kill bacterial e.g.mint and witch hazel
    -other plants produce poisons to stop herbivores eating them
  • what are mechanical defences
    -thorns and hairs to stop animals touching/eating them
  • What are other mechanical defences
    Leaves droop or curl when something ouches them ,they can knock insects off and move away from things
    some plants mimic other organisms