AQA GCSE Biology

Plant disease & defences

AQA GCSE Biology revision on Plant disease & defences. Aligned to the AQA GCSE Biology 8461 specification. This bank has 25 practice questions on this topic.

Sample questions (3 of 25)

Question 1

Which physical barrier primarily prevents the entry of pathogens into the leaf tissue?
- A) Cellulose cell wall
- B) Waxy leaf cuticle
- C) Stomata guard cells
- D) Vascular bundle
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Answer: Waxy leaf cuticle

The waxy cuticle is a surface layer that prevents the entry of bacteria and fungi by acting as a physical seal. While the cellulose cell wall provides structural support, the cuticle is the outermost protective barrier that specifically blocks pathogen penetration.
Question 2

What chemical defence do plants produce to specifically deter herbivores from consuming their leaves?
- A) Antibiotic resins
- B) Poisonous toxins
- C) Cellulose fibres
- D) Antiseptic oils
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Answer: Poisonous toxins

Plants produce a variety of chemical defences including poisons to reduce the likelihood of being eaten. These toxins are specifically evolved to interfere with the metabolism or digestion of the herbivore, effectively deterring feeding.
Question 3

Which plant response involves the rapid shedding of leaves to remove pathogens?
- A) Leaf abscission
- B) Active transport
- C) Stomatal closure
- D) Xylem thickening
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Answer: Leaf abscission

By dropping infected leaves, the plant effectively removes the pathogen from the main body of the organism. This process, known as abscission, prevents the spread of the infection to the stem and roots.

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Sample questions (3 of 25)

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