Plant defence responses

• What are the three main defense systems in plants against attack?

  Physical responses, chemical responses, mechanical responses
• How do plants physically defend themselves against microorganisms?

  Through cellulose cell walls and waxy cuticles
• What is the function of the cellulose cell wall in plants?

  It is difficult for microorganisms to penetrate
• What is the role of the waxy cuticle on leaves?

  It protects against penetration by microorganisms
• What happens to bark as it ages?

  It falls off and is replaced by fresh bark
• What are chemical responses in plants?

  Releasing chemicals to protect against attack
• What type of chemicals can plants release to deter herbivores?

  Poisonous chemicals
• What is the mechanical defense system in plants?

  Physical structures that deter herbivores
• How do thorns protect plants?

  They prevent herbivores from eating the plant
• What effect do irritating hairs on plants have on herbivores?

  They make the plant difficult to eat
• What happens to plants with leaves that droop or curl when touched?

  They may scare herbivores away
• What is mimicry in plants?

  Resembling other plants to avoid being eaten
• How does the white dead nettle protect itself?

  It mimics the stinging nettle
• Why are herbivores less likely to eat white dead nettle?

  They mistake it for a stinging nettle
• What are the types of plant defenses against attack?

  • Physical responses
  • Cellulose cell walls
  • Waxy cuticles
  • Bark
  • Chemical responses
  • Antibacterial chemicals
  • Poisons to deter herbivores
  • Mechanical responses
  • Thorns and hairs
  • Drooping or curling leaves
  • Mimicry