Plant Diseases

• 3 ways of detecting a plant disease

  Stunted growth

  Spots on leaves

  Decay
• 3 ways of identifying plant diseases

  Use of gardening manual

  Use of Laboratory

  Use of testing kits containing monoclonal antibodies
• 4 possible causes of plant diseases

  Viruses

  Bacteria

  Fungi

  Insects
• How do aphids damage plants?

  Pierce stems with their mouthparts to drink sugary liquid in phloem, introduce pathogens and deprive plants of sugars.
• 2 problems caused in plants by an ion deficiency

  Stunted growth by nitrate deficency

  Chlorosis by magnesium deficency
• Why do lack of nitrate ions affect plant growth?

  They are used to make proteins
• Why do magnesium ions affect plant growth?

  Chlorophyll
• 3 physical defences of plants

  Cellulose cell walls

  Tough waxy cuticle on leaves

  Layers of dead cells on bark of trees falling off
• 2 chemical defenses of plants

  Poisons countering herbivores

  Antibacterial chemicals
• 3 mechanical defences of plants

  Thorns detering animals

  Mimicry tricking animals

  Leaves dropping when touched