1
Triple only
[2 marks](a) What is meant by food security? (1) (b) Give one biological factor that threatens food security. (1)
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- (a) having enough food to feed a population (1)
- (b) any one from: increasing birth rate / changing diets in developed countries / new pests and pathogens / environmental change such as failure of rains / cost of agricultural inputs / conflict affecting availability of water or food (1)
2
Triple only
[3 marks]Some farmers keep food animals in small pens at a controlled temperature. Explain how this increases the efficiency of food production.
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- animals move less, so less energy is transferred to the surroundings / less glucose used in respiration for movement (1)
- warm surroundings, so less energy is used to keep warm / less heat lost (1)
- so more of the energy / biomass from food is used for growth (1)
3
Triple only
[3 marks]Explain how control of net size and fishing quotas help to conserve fish stocks.
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- larger mesh lets small / young fish escape (1)
- they grow and breed (1)
- quotas limit the amount caught so enough fish are left to breed (1)
4
Triple only
[4 marks](a) Describe how the protein-rich food mycoprotein is produced. (3) (b) Name the substance made by a genetically modified bacterium that is used to treat diabetes. (1)
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- (a) the fungus Fusarium is used (1)
- grown on glucose syrup (1)
- in aerobic conditions (1)
- the biomass is harvested and purified (1)
- Max 3 for (a)
- (b) human insulin (1) allow insulin