7.5 Food Production

What is food security?

Having enough food to feed a population.

What are the biological factors which are threatening food security? (6)

• Increasing birth rate → more food required

• Changing diets in developed countries → already scarce food resources are transported around the world

• New pests and pathogens → destroy crops

• Environmental changes — e.g. famine in some countries is rains fail

• Cost of agricultural inputs

• Conflicts → affects availability of water and food

How can the efficiency of food production be improved?

Restricting energy transfer from food animals to the environment.

• Farmers aim to increase the amount of energy (from food) that is converted to biomass in livestock because this is more efficient.

• This is done by restricting energy transfer from food animals to the environment.

Explain how this is done.

• Limiting their movement — e.g. small cages

  • This reduces the energy wasted on movement

• Controlling the temperature of their surroundings — less energy wasted on controlling body temperature

• Given high protein food → increases growth

Explain the ethical objections with intensive farming.

• Animals are kept in a small space → causes distress

• Increases the risk of spread of infection

• Standard of living is low for the animals

How do farmers decrease the risk of spread of infection in intensive farming, what is the risk of this?

• Giving animals precautionary antibiotics

• Contributes to antibiotic resistant bacteria

Evaluate the advantages and disadvantages of modern farming techniques.

• Produces a higher yield of food

• Makes more efficient use of land

• Increased risk of disease spreading

  • Antibiotics given → increases risk of developing antibiotic resistant bacteria

• Ethical objections — e.g. poor standard of living

• Intensive crop farming practices → reduces biodiversity

How can intensive crop farming reduce biodiversity? (2)

• Growing only one type of crop — monoculture

• Removing hedgerows — makes fields larger

• Fish stocks in the oceans are declining.

Explain why this is happening.

Humans are fishing faster than the populations can regenerate.

• _______ ________ in the oceans are declining.

• It is important to maintain _____ ________ at a level where __________ continues or certain species may ___________ altogether in some areas.

• Fish stocks

• fish stocks

• breeding

• disappear

What restrictions have been put in place to conserve fish stocks? (2)

• Control of net size

• Fishing quotas

How does controlling net sizes help conserve fish stocks?

• Making nets bigger → smaller fish can get through

  • Can reach breeding age and produce more fish

How do fishing quotas help conserve fish stocks?

Only a certain number of a species of fish can be caught → prevents overfishing

What is Fusarium used to produce? How is it produced?

• Mycoprotein — protein-rich food for vegetarians

• Fungus is grown on glucose syrup (aerobic conditions) — biomass is harvested and purified

How can biotechnology be used? (2)

• Feed the population

• Provide treatments for diseases

How doe the use of mycoprotein have a positive impact?

• Reduces land use — less land used to rear animals and grow crops

• Reduces methane contribution — cows produce methane → less cows being reared

• A _____________ modified bacterium produces human _________.

• When harvested and __________ this is used to treat people with __________.

• genetically

• insulin

• purified

• diabetes

What are the advantages of using genetically modified crops?

• Resistance to pests or extreme weather conditions — increased yields

• Increases nutritional value — beneficial where there is a lack of access to vitamins (e.g. golden rice)

• It is more energy-efficient to rear cows indoors than to rear cows outdoors.

Give two reasons why. [2 marks]

• Less energy lost as heat

• Less energy lost in movement

Suggest two possible disadvantages of rearing cows indoors. [2 marks]

• Increased spread of disease

• Extra cost of heating

• Too many herring were caught by fishermen between 1960 and 1977.

• Herring can live for up to 12 years and begin to reproduce when 3 to 4 years old.

• Laws have been introduced to help conserve herring:

  • 1977 to 1981 – herring fishing was banned in the North Sea

  • 1984 to present day – control of mesh size of fishing nets

  • 1997 to present day – fishing quotas were introduced

  • 1998 to present day – herring fishing was banned in breeding grounds during the breeding season

• Figure 11 shows how the biomass of adult herring in the North Sea has changed box between 1950 and 2010.

• Figure 12 shows how a minimum mesh size helps to conserve herring

Evaluate the effect of these laws on the conservation of herring stocks. [6 marks]

Use data from Figure 11 and information from Figure 12 in your answer.

• Small fish are not caught — can live long enough to reproduce

• Biomass has generally increases after laws are introduced

• ‘77 to ‘81 law resulted in an increase in biomass — 0.9 by ‘84

• ‘84 law resulted in an increase in biomass — 0.9 to 1.8

• ‘97 law resulted in increase — 1.15 to 1.25

• ‘98 law resulted in increase — 1.25 to 2.5

• Each law results in an increase followed by a decrease

• Laws superimposed so can’t tell the effect of each

• Bans during breeding seasons are the most effective on conserving herring stocks as they had the largest increase

• Genetic modification of crop plants can help meet the demands of the increasing human population.

• Golden rice is a genetically modified (GM) crop

What is the advantage of golden rice compared with non-GM rice? [1 mark]

Golden rice has improved nutritional value

• Genetic modification of crop plants can help meet the demands of the increasing human population.

• Golden rice is a genetically modified (GM) crop

Suggest one reason why some people are concerned about the use of golden rice. [1 mark]

Genes may contaminate other species.