Protecting Plants

• Physical defences

  • Waxy cuticle
  • Increase strength to make it harder to penetrate
  • Contain self-defence to contain disease
• Bark - physical defence


  • lignin layer to stop pathogens entering
  • Hard for pests to get through
• Chemical defences

  • Antibacterial chemicals
  • Released to kill bacteria
• Mechanical defences - curled leaves

  • Curls leaves to protect itself
  • Looks less attractive to predators
• Thorns - mechanical defence


  • Protects sharp objects
  • Predators cannot eat it
• Camouflage - mechanical defence 


  • Blends in so can protect
  • Predators cannot find plant
• Plant Deficiencies

  • Nitrate deficiency -> stunted growth (nitrates needed for protein synthesis = growth)
  • Magnesium deficiency -> leaves turn paler (needed to make chlorophyll)
  • Magnesium needed for chloroplasts