7.18 Food security and farming
5 exam questions worth 11 marks. Write your answer, open the mark scheme, then give yourself the marks you earned. Your answers are saved on this device.
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What is meant by food security?
Mark scheme
having enough food to feed a population
Model answer
Food security means having enough food to feed a population.
Give three factors that threaten food security.
Mark scheme
Any three from:
- increasing birth rate / population (1)
- changing diets (1)
- new pests / pathogens (1)
- environmental change / drought / floods (1)
- cost of agricultural inputs (1)
- conflict (1)
Model answer
A growing population, new pests and pathogens, and environmental changes such as drought.
Chickens are reared indoors in small, heated pens. Explain why this increases the efficiency of food production, and give one objection to it.
Mark scheme
- less movement so less energy used / less respiration (1)
- kept warm so less energy used to keep warm (1)
- so more biomass / food gained (1)
- objection: animal welfare / cruelty / disease spreads easily (1)
Maximum 3 marks
Model answer
Limiting movement and keeping the chickens warm means they use less energy in respiration, so more of their food becomes biomass. However, many people object because of the animals' welfare.
Explain how fishing quotas and net mesh size help keep fish stocks sustainable.
Mark scheme
- quotas limit the number of fish caught (1)
- larger mesh lets young / small fish escape to grow and breed (1)
Model answer
Quotas limit how many fish are caught, and a bigger mesh lets young fish escape so they can grow and breed.
Give one advantage and one disadvantage of biological control.
Mark scheme
- advantage: no chemicals / no pollution / long lasting / specific (1)
- disadvantage: control species may become a pest / eat other species / slow (1)
Model answer
It avoids using harmful chemicals, but the introduced predator could become a pest itself.
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