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?

  They have a cellulose cell wall
• What role does the waxy cuticle play in plant defense?

  It prevents microorganisms from penetrating
• What is a physical barrier found on tree stems?

  Bark
• What happens to bark as it ages?

  It falls off and is replaced
• What is the chemical response in plants?

  Release of antibacterial chemicals and poisons
• What do antibacterial chemicals do for plants?

  They kill bacteria and prevent attacks
• How do poisons help plants defend against herbivores?

  They deter herbivores from grazing
• How do thorns protect plants?

  They prevent herbivores from eating them
• What effect do irritating hairs have on herbivores?

  They make the plant difficult to eat
• What is the purpose of leaves that droop or curl when touched?

  To scare herbivores by moving
• What is mimicry in plant defense?

  Resembling other plants to avoid being eaten
• What plant resembles a stinging nettle but has no sting?

  White dead nettle
• Why are herbivores less likely to eat white dead nettle?

  It resembles a stinging nettle
• What are the types of plant defense mechanisms?

  • Physical responses
  • Cellulose cell wall
  • Waxy cuticle
  • Bark
  • Chemical responses
  • Antibacterial chemicals
  • Poisons
  • Mechanical responses
  • Thorns and hairs
  • Drooping or curling leaves
  • Mimicry
• How can you describe the defense mechanisms of plants against attacks?

  • Plants use physical barriers like cell walls and bark.
  • They release chemicals to deter pests.
  • Mechanical defenses include thorns and mimicry.