Infection & ResponseDeep Dive

Plant Defense Mechanisms

Part of Plant Diseases and Defenses · GCSE GCSE Biology revision

This deep dive covers Plant Defense Mechanisms within Plant Diseases and Defenses for GCSE Biology. Plant pathogens, defense mechanisms, disease identification, crop protection It is section 7 of 18 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 7 of 18

Practice

22 questions

Recall

21 flashcards

Plant Defense Mechanisms

Physical Defenses

Waxy Cuticle
  • Waterproof layer on leaves
  • Prevents pathogen entry
  • Reduces water loss
  • Especially thick in desert plants
Cell Walls
  • Made of tough cellulose
  • Physical barrier to penetration
  • Provide structural support
  • Can thicken in response to attack
Bark
  • Thick, protective outer layer
  • Dead cells form barrier
  • Protects inner living tissue
  • Contains antimicrobial compounds
Thorns and Spines
  • Deter herbivores
  • Prevent physical damage
  • Reduce pathogen transmission
  • Modified leaves or stems

Chemical Defenses

Types of Chemical Compounds
  • Antimicrobial proteins: Directly kill bacteria and fungi
  • Antifungal compounds: Prevent fungal growth and spore germination
  • Antiviral proteins: Interfere with virus replication
  • Toxins: Poisonous to pathogens and herbivores
  • Enzyme inhibitors: Block pathogen enzymes
Production and Response
  • Constitutive: Always present as baseline protection
  • Induced: Produced rapidly in response to attack
  • Systemic: Warning signals sent throughout plant
  • Local: Concentrated at site of infection

Keep building this topic

Read this section alongside the surrounding pages in Plant Diseases and Defenses. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Plant Diseases and Defenses

What type of pathogen causes rose black spot disease?

  • A. Fungus
  • B. Virus
  • C. Bacterium
  • D. Protist
1 markfoundation

Explain how rose black spot affects the growth of infected plants.

2 marksstandard

Quick Recall Flashcards

What is rose black spot?
A fungal disease that affects roses, causing black or purple spots on leaves, which turn yellow and drop off, reducing photosynthesis.
What is a plant pathogen?
A microorganism that causes disease in plants, such as fungi, bacteria, or viruses.

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