Food Production

(Biology only — 4.7.5.1) Food security is having access to enough safe, nutritious food for a healthy and active life. It's not just about quantity — it's about:

• Availability — enough food being produced.
• Access — affordability for households.
• Quality — safe to eat, nutritious.
• Reliability — consistent supply, not just in good years.

When any of these break down, food security is at risk.

Global picture (UN data 2024):

• ~700 million people face hunger every day.
• ~2.3 billion experience some food insecurity (skipping meals).
• ~3.1 billion can't afford a healthy diet.

UK picture:

• UK is a wealthy country but ~7% of households experience food insecurity (Food Foundation data 2023).
• Food bank use has risen sharply since 2010 (cost-of-living crisis).
• UK imports ~40% of food consumed — heavily reliant on EU, Africa, Asia.

Why this matters biologically. Food security depends on ecosystems — soil, pollinators, climate, water. The same biology that maintains biodiversity (4.7.3.6) keeps our food supply going.

1. Increasing birth rate / population growth. The world population has grown from 2 billion (1927) to 8 billion (2022) — a 4× increase in one human lifetime. By 2050 it may reach 9.7 billion. More people means more food needed.

In some developing countries, birth rates remain high, and food production hasn't kept up.

2. Changing diets in developed countries. As nations get richer, people eat more meat, dairy and processed food. This means:

• More land needed (because of the 10% biomass rule — see 4.7.4.3).
• More water and feed (1 kg beef needs ~15,000 L water; 1 kg wheat needs ~1,500 L).
• More CO₂ and methane emissions.
• Crops fed to animals instead of people (e.g. UK uses ~40% of cereal crop for animal feed).

3. New pests and pathogens affecting farming.

• Wheat rust (a fungal disease) wipes out wheat in entire regions.
• Cassava brown streak virus devastates African staple crops.
• Bird flu (avian influenza) — UK poultry losses in 2022-23 cost millions.
• Foot and mouth outbreaks (UK 2001) killed 6 million animals.
• Locusts — recent East African outbreaks 2020-21.

Climate change is helping new pests spread to new areas (warmer winters = pests survive year-round).

4. Environmental changes — drought, flooding, soil loss.

• Droughts cut harvests dramatically (UK 2022 = poor wheat yields).
• Flooding destroys crops and ruins soil (UK 2024 wet winter delayed planting).
• Soil erosion from intensive farming reduces fertility.
• Climate change shifts rainfall patterns — some regions getting too dry, others too wet.

5. Cost of agricultural inputs.

• Fertiliser prices doubled in 2022 due to gas price rises (war in Ukraine).
• Diesel for tractors got more expensive.
• Higher prices = farmers can afford less = lower yields = higher food prices.
• This hits poorer countries hardest.

6. Conflicts affecting food availability or access.

• War in Ukraine (2022-) disrupted huge global wheat and sunflower oil supplies.
• Civil wars (Yemen, Sudan, Syria) destroy farms and infrastructure.
• Conflict makes farming impossible AND blocks food aid.

These factors INTERACT. Drought (factor 4) plus expensive fertiliser (factor 5) plus war disrupting imports (factor 6) creates a perfect storm — exactly what happened in 2022-23 when world food prices reached record highs.

Production-side solutions (more food, sustainably):

• More efficient farming — better seeds, irrigation, integrated pest management.
• Genetic modification of crops for drought/pest resistance (controversial).
• Vertical farming — growing crops in stacked indoor systems (uses less land).
• Aquaculture (fish farming) — supplies ~50% of fish eaten globally now.
• New protein sources — insects, mycoprotein (Quorn), lab-grown meat.

Demand-side solutions (use food more efficiently):

• Reduce meat consumption — frees up huge amounts of land/water.
• Reduce food waste — UK households waste ~6 million tonnes/year (~30% of food bought).
• Reduce biofuel competition — using crops for fuel raises food prices.

Political/economic solutions:

• Support farmers — fair prices, subsidies for sustainable practices.
• Stable trade — avoid protectionism and trade wars.
• Climate action — reduce CO₂ to slow climate-driven shocks.
• Population planning — education + family planning in high-growth countries.

UK-specific actions:

• Sustainable Farming Incentive (replacing EU subsidies).
• Food Strategy (Henry Dimbleby, 2021) calling for less meat, more veg.
• Investment in aquaculture (Scottish salmon farming, mussel farming).
• Plant breeding research (John Innes Centre, Norwich).

The big picture. We need to produce more food while using LESS land, water and emissions. AQA wants you to show you understand the trade-offs.

(Biology only — 4.7.5.2) Recall from 4.7.4.3 that only ~10% of biomass transfers between trophic levels. The rest is lost to respiration, movement, body heat, faeces and excretion.

If farmers can reduce these losses, more of the feed's biomass ends up as meat/eggs/milk — making food production more efficient (more food per unit of feed).

Three main techniques:

1. Limit movement. Less movement = less muscle activity = less respiration = less energy 'wasted'. Examples:

• Battery cages for hens — small cages preventing them moving.
• Veal crates (now banned in UK) — calves kept in stalls so they don't develop muscle.
• Slatted barns — pigs kept in pens with limited space.
• Tethering dairy cows.

2. Control temperature. Endotherms (mammals, birds) use lots of energy keeping body warm in cold conditions. If the barn is kept at the right temperature:

• Less energy used to generate body heat.
• More energy available for growth.
• Especially important for young animals (chicks, piglets) — they have a high surface-area-to-volume ratio and lose heat fast.

UK broiler chicken sheds are typically kept at 28–32°C.

3. High-protein feed. Protein in feed provides amino acids for building new muscle tissue. Cereal grains (wheat, barley) are mixed with protein-rich ingredients:

• Soya bean meal (imported from Brazil/Argentina — links back to deforestation 4.7.3.4).
• Fishmeal (links to overfishing 4.7.5.3).
• Amino acid supplements (lysine, methionine).

This makes animals grow faster and reach slaughter weight sooner — less days alive = less feed needed = more efficient.

The result. A modern UK broiler chicken reaches slaughter weight (~2.2 kg) in just 35-42 days — compared to ~100+ days in the 1950s. Pigs reach slaughter at ~6 months. Dairy cows produce ~3× more milk than in 1950.

Intensive farming techniques are efficient but raise serious concerns. AQA expects you to evaluate the trade-offs.

1. Animal welfare.

• Restricted movement causes stress, boredom, abnormal behaviours (feather-pecking in hens, tail-biting in pigs).
• Crowded conditions = injuries.
• Many UK consumers find intensive farming ethically objectionable.
• Animal welfare laws have tightened: UK banned barren battery cages for hens in 2012, sow stalls in 1999.

2. Disease spread.

• Animals in close contact → diseases spread fast.
• UK avian flu outbreaks 2022-23 (millions of birds culled).
• Foot and mouth 2001 — 6 million animals culled.
• Risk of new diseases jumping to humans (zoonotic) — concerns about pandemic risk.

3. Antibiotic overuse.

• Antibiotics often added to feed to prevent disease in crowded conditions.
• Drives antibiotic resistance — a global health crisis.
• UK has cut farm antibiotic use ~50% since 2014, but still significant.

4. Environmental impact.

• Animal waste (slurry) pollutes rivers — UK rivers heavily polluted by intensive pig and dairy farms.
• Methane from cattle (greenhouse gas).
• Ammonia emissions damage local plants.
• Feed crops drive deforestation (soya from Brazil).

5. Worker conditions.

• Slaughterhouse and intensive farm workers face hard, sometimes dangerous conditions.

Alternatives:

• Free-range — animals have outdoor access (UK eggs commonly labelled).
• Organic — strict welfare + no routine antibiotics + no GM feed.
• Pasture-fed — cattle eat only grass, no concentrates.
• RSPCA Assured label — independent welfare certification.

Evaluation framework:

For intensive	Against intensive
More food, lower price	Poor animal welfare
Less land per unit	Disease risk
Predictable supply	Antibiotic resistance
Year-round production	Pollution, methane

The bigger question. As global meat demand rises, can intensive farming feed everyone affordably? Or are higher-welfare and lower-meat diets the answer? AQA evaluation questions want both sides.

UK welfare standards. UK animal welfare law is among the strictest globally. Key rules:

• Hens: barren battery cages banned (2012); 'enriched' cages still allowed but free-range and barn eggs are growing.
• Pigs: sow stalls banned (1999); tail-docking restricted.
• Calves: veal crates banned (1990s).
• Slaughter: stunning required before slaughter.
• Halal/kosher religious slaughter is exempt from stunning rules but still tightly regulated.

Egg labels (in UK shops):

• Class 0 — Organic (highest welfare, free-range + organic feed).
• Class 1 — Free-range (outdoor access).
• Class 2 — Barn (indoor but no cages).
• Class 3 — Caged (enriched cages, still used).

Chicken labels:

• Higher welfare / RSPCA Assured / Free range — slower-growing, more space.
• Standard supermarket 'fresh chicken' is usually intensive indoor.

Beef/lamb labels:

• Grass-fed, Pasture for Life, Organic — higher welfare and environmental standards.

Consumer pressure has driven big changes: M&S, Waitrose and Co-op only sell free-range or higher-welfare eggs; many UK schools serve only free-range eggs.

Trade and Brexit angle. Some imported food (US, Brazil) uses farming methods banned in the UK. UK farmers worry about 'unfair competition'; consumers worry about lower standards entering the food chain.

(Biology only — 4.7.5.3) Wild fish are a vital food source — providing ~17% of animal protein eaten globally, and a major UK industry (Scotland, NE England, SW England).

But many fish stocks are in serious trouble. According to the UN Food and Agriculture Organization (FAO):

• ~35% of world fish stocks are overfished (caught faster than they can reproduce).
• ~58% are at maximum sustainable level (cannot take more).
• Only ~7% are underfished (room to grow catches).

Why fisheries collapse. Fish populations follow a simple rule: as long as you only catch the 'surplus' fish each year, the population stays steady. But if you take more than that, the breeding population shrinks → fewer fish next year → catches fall → fewer fish the year after.

Modern fishing technology is the problem.

• Massive trawl nets scoop up everything in their path.
• Sonar finds fish shoals precisely.
• Refrigerated factory ships can fish far from port for weeks.
• Subsidies keep fleets too big for the available fish.

UK examples of overfishing.

• Atlantic cod in the North Sea collapsed in the 2000s after decades of overfishing.
• Bluefin tuna in the Mediterranean nearly disappeared before quotas were tightened.
• Atlantic salmon wild stocks are at record lows.

The Grand Banks lesson. The Newfoundland cod fishery (off Canada) collapsed catastrophically in 1992 after centuries of fishing. 30,000 fishers lost their jobs in a few months. Despite a fishing ban, the stock still hasn't fully recovered 30+ years later. Once a fishery collapses, recovery is slow or impossible.

1. Net mesh size control.

Fishing nets have a mesh size — the size of the holes. Different mesh sizes catch different sizes of fish.

Idea: Use larger mesh size so that small, young fish escape through the holes and live to grow up, breed, and replenish the population.

For example, in UK waters, cod nets must have a minimum mesh size of 120 mm — small cod (under ~35 cm) can escape. This is set by scientific advice based on the fish's growth and breeding age.

Result: Catches mainly mature fish that have already bred at least once, so the population can replace itself.

2. Fishing quotas.

A quota is a legal limit on how much fish can be caught in a year, set per species, per area, per country. UK quotas come from:

• Scientific assessment of fish stocks (ICES — International Council for the Exploration of the Sea).
• Government allocation between fishing fleets.

Idea: Limit the total catch to leave enough breeding fish in the sea.

UK example: Cod quota in the North Sea has fluctuated as stocks recovered/declined. Tight quotas in the 2000s helped North Sea cod start to recover.

Enforcement: Boats must log catches; observers and satellites monitor; fines for over-fishing.

3. No-fishing zones (Marine Protected Areas / MPAs).

Some sea areas are completely closed to fishing — or only allow specific gentle methods (line-fishing, no trawling).

Idea: Give fish a safe place to breed and grow. Excess fish then spill over into surrounding fished areas.

UK example: Lyme Bay MPA (Devon) — bottom trawling banned in 2008. Within years, scallops, lobster and crab populations bounced back; nearby fishing improved. UK has now designated Marine Protected Areas in ~38% of UK waters — but enforcement is patchy in some zones.

Short-term costs:

• Lower catches initially — fishers earn less.
• Job losses as fleets shrink (e.g. UK Scottish fishing fleet has shrunk by ~30% since 1995).
• Fishing communities decline (Grimsby, Hull, Peterhead all hit hard).
• Imported fish increases to fill UK demand — fish imports cost £4+ billion/year.

Long-term benefits:

• Fish stocks recover — North Sea cod has partly recovered since 2010 thanks to tight quotas.
• Fishery has a future — industry can continue indefinitely.
• Healthier marine ecosystem — protected zones support biodiversity (whales, dolphins, seabirds, corals).
• Better catches eventually — once stocks rebuild.

The 'tragedy of the commons'. Fish stocks are a shared resource. Without management, every fisher has an incentive to catch as much as possible (because if I don't, someone else will). This destroys the resource for everyone. Government regulation is the only way to solve this.

International cooperation matters. Fish don't respect borders — a cod swims between UK, Norwegian and Icelandic waters in one lifetime. EU Common Fisheries Policy (CFP) historically managed quotas; after Brexit the UK negotiates its own quotas but still works internationally (UN, NEAFC).

Consumer pressure helps:

• Marine Stewardship Council (MSC) logo on fish products — guarantees sustainable source.
• UK supermarkets (Waitrose, M&S, Sainsbury's) source most fish from MSC-certified fisheries.
• Avoiding endangered species (bluefin tuna, eel, skate) helps stocks recover.

Conclusion (good for exam evaluation answers): Sustainable fishing involves real costs for current fishers but secures the long-term future of both ecosystems and the fishing industry. The alternative — collapse — is worse for everyone.

(Biology only — 4.7.5.4) Mycoprotein (literally 'fungus protein') is a food made from the fungus Fusarium venenatum. It was developed in the UK in the 1960s-70s and launched commercially in 1985 as Quorn.

Why mycoprotein matters:

• High in protein — similar protein content to beef (~12 g per 100 g).
• Low in saturated fat — much lower than red meat.
• High in fibre — most meats have none.
• Vegetarian/vegan-friendly (vegan versions exist).
• Far lower carbon footprint than beef — about 1/10th the CO₂ per kg.
• Uses much less land and water than livestock.

How it's produced — in a fermenter:

A fermenter is a large stainless-steel vessel where microorganisms are grown under controlled conditions.

1. Sterile glucose syrup is added as food for the fungus (the syrup comes from wheat or maize).
2. Ammonia and minerals are added as a nitrogen source (for protein) and nutrients.
3. The fungus Fusarium is added — it grows by aerobic respiration.
4. Air (oxygen) is pumped in continuously — Fusarium needs O₂ to respire and grow.
5. A water-cooled jacket removes the heat produced by respiration — fungi grow best at ~28-30°C.
6. An agitator/stirrer mixes the contents so all the fungi get oxygen and food.
7. pH is controlled by adding acid or alkali — fungus grows best around pH 6.
8. After several days, the mycoprotein biomass is harvested, dried, processed and shaped into Quorn 'chicken pieces', 'mince' etc.

Why fermenters are essential:

• Provide controlled conditions for fastest growth.
• Keep everything sterile — no contamination by other microbes.
• Allow continuous production at industrial scale.
• The same principle is used for insulin, antibiotics, beer, yoghurt — all made in fermenters.

Genetic modification (GM) means changing an organism's DNA by adding, removing or altering genes. In crop plants, GM has been used to:

1. Improve crop yield.

• GM herbicide-resistant crops (e.g. Roundup-Ready soya) — farmers can spray weedkiller without harming the crop.
• Easier weed control = bigger harvests.

2. Pest resistance.

• Bt maize, Bt cotton — modified with a gene from the bacterium Bacillus thuringiensis that produces a toxin lethal to certain insects.
• Plants make their own insecticide → less chemical spraying needed.

3. Drought / cold / salt resistance.

• Important for marginal land or climate change.
• Several GM drought-tolerant maize varieties grown in Africa.

4. Improved nutritional value — golden rice.

• Golden rice is rice modified to contain a gene that produces beta-carotene (which the body converts to vitamin A).
• Designed to fight vitamin A deficiency in poor rice-dependent populations (~250,000 children go blind each year from vitamin A deficiency).
• Approved in the Philippines (2021) and Bangladesh.

How GM works (brief):

1. Identify a useful gene in one organism (e.g. Bt toxin gene in bacterium).
2. Cut the gene out using restriction enzymes.
3. Insert it into a vector (often a bacterium's plasmid or virus).
4. Use the vector to transfer the gene into the crop plant's cells.
5. Grow up the modified cells into whole plants.
6. The new plant produces the protein from the inserted gene.

(More detail in topic 4.6 Inheritance, variation and evolution.)

Benefits of GM crops:

• Higher yields → food security.
• Less pesticide use (with Bt crops).
• Added nutrition (golden rice).
• Drought tolerance helps marginal areas.

Concerns:

• Cross-pollination with wild plants — GM genes could spread.
• Insect resistance could build up in pest populations.
• Effects on non-target species (e.g. bees, butterflies).
• Corporate control — most GM seeds are patented and farmers can't save seed.
• Ethical/cultural concerns — 'unnatural', 'playing God'.

UK/EU position. GM crops are NOT widely grown in UK or EU due to public opposition and tight regulation. The UK approved its first GM crop trial in 2018 (wheat resistant to disease). Most GM foods sold in UK are imported (animal feed soya from US/Brazil).

Benefits of biotechnology for food production:

• Mycoprotein: efficient, low-emission protein source; uses tiny amounts of land/water vs beef.
• GM crops: higher yields, less pesticide, drought/salt resistance, added nutrition.
• Aquaculture biotech: faster-growing fish, disease resistance.
• Fermenter production can be sterile, predictable, year-round.

Concerns about biotechnology:

• GM ecological: gene escape to wild plants, resistance in pests, harm to non-target insects.
• GM economic: corporate monopoly on patented seeds; farmer dependence.
• GM ethical: 'unnatural'; cultural/religious objections.
• Mycoprotein: low concerns biologically, but some find taste/texture unfamiliar; production needs reliable energy supply.
• Public perception — many UK consumers distrust GM food.

Real-world case: Quorn.

• Launched 1985 in UK.
• Now sold in 20+ countries.
• Annual sales >£200 million.
• 14× less water and 25× less land per kg protein than beef.
• Accepted by UK consumers — not controversial.

Real-world case: golden rice.

• Developed in 2000.
• Took 20+ years to get regulatory approval (Philippines 2021).
• Could prevent ~500,000 cases of childhood blindness/year.
• Opposed by some anti-GM groups; supported by many scientists.

Conclusion (for evaluation answers). Biotechnology offers powerful tools for tackling food security and malnutrition. Each application needs to be evaluated on its own merits — mycoprotein (Quorn) is widely accepted; golden rice has clear humanitarian benefits; Bt crops reduce pesticide use but raise resistance concerns. Sensible regulation, not blanket bans or blanket approval, is the way forward.