Question 1
Triple only (what this means)
Triple only: only in Triple Biology. Combined Science students can skip it. What the labels meanDescribe two physical barriers that help to protect plants from pathogens.
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- leaf cuticle: a waxy layer that pathogens cannot easily pass through (1)
- cell wall: a strong layer around the cell that pathogens must get past (1) allow made of cellulose
Question 2
Triple only (what this means)
Triple only: only in Triple Biology. Combined Science students can skip it. What the labels meanSome plants make chemicals as a defence against attack. State one way these chemicals protect the plant and one way they can be used by humans.
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- kill / slow the growth of microorganisms, or poison pests (1) allow deter pests from eating the plant
- used as medicines to treat disease or relieve symptoms (1) allow a named example such as aspirin from willow
Question 3
Triple only (what this means)
Triple only: only in Triple Biology. Combined Science students can skip it. What the labels meanHigher tier (what this means)
Higher tier: only on the Higher tier papers. Foundation students can skip it. What the labels meanA farmer notices spots on the leaves of some of her tomato plants. Describe how the cause of the spots could be found.
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- eliminate environmental causes, for example check soil nutrients, water supply or temperature (1)
- record where the affected plants are / distribution analysis, for example clusters around one point suggest a spreading pathogen (1)
- observe the visible symptoms and compare them with known diseases (1)
- diagnostic tests in a laboratory to identify the pathogen (1)