Exam Focus

Exam Focus

Medium Frequency Specific Examples Required Compare Questions Common

Edexcel 1BI0 Paper 2 (Topic 6: Plant Structures and Their Functions) includes plant diseases and defences with scenario-based questions — you may be given an image of leaf symptoms or data on disease spread and asked to "Suggest" the type of pathogen or the appropriate control method. Named examples (rose black spot, TMV) are expected. The "Suggest" command word is used heavily on Edexcel for unfamiliar disease contexts.

• 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.