This exam focus covers Exam Focus within Plant Diseases and Defenses for GCSE Biology. Plant pathogens, defense mechanisms, disease identification, crop protection It is section 16 of 18 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Topic position
Section 16 of 18
Practice
18 questions
Recall
20 flashcards
Exam Focus
AQA Medium Frequency Specific Examples Required Compare Questions Common
- Always name specific diseases: "Rose black spot" and "TMV" score more marks than "a fungal disease" or "a viral disease". Learn both names and their pathogen types.
- Link symptoms to impact: Never just describe a symptom. Explain the consequence — black spots cause yellowing which reduces chlorophyll which reduces photosynthesis which reduces growth.
- Physical vs chemical — give examples: Examiners want you to state a defense AND explain how it works. "Waxy cuticle — hydrophobic, prevents spore germination on leaf" is better than just "waxy cuticle".
- Compare with human immunity: A common 4-mark question asks you to compare plant and animal defenses. Plants: physical barriers + chemical compounds. Animals: also have mobile white blood cells, specific antibodies, and immune memory.
- Disease identification from symptoms: Mosaic/mottling = likely virus; spots with surface growth = likely fungus; wilting = likely bacteria or root disease. Use the pattern to justify your answer.