7.5 Food production

7.5.1 Factors affecting food security

FSL: GCSE Biology Revision "Food security"

- Food security is having enough food to feed a population.
- Sustainable methods must be found to feed all people on Earth.
- These biological factors affect food security:

Factor	Effect
The increasing birth rate	This has threatened food security in some countries as, obviously, more food is needed to feed the growing population.
Changing diets in developed countries	This means scarce food resources are transported around the world to feed richer countries, which may lead to food shortages in poorer countries. This is especially problematic because rich countries eat more meat, which takes a lot more land and resources to produce.
New pests and pathogens	These affect farming, which can lead to food shortages, especially if there is an outbreak of a disease (like bird flu killing chickens in the US).
Environmental changes	Climate change, for example, can cause droughts, floods, and other extreme weather events that can destroy crops and reduce food production. If rain does not fall as much as usual, harvests and be significantly reduced.
The cost of agricultural inputs	The cost of inputs like fertiliser, pesticides, machinery, and water can increase, which can make farming too expensive.
Conflicts	Conflicts can disrupt food production, especially if there is a shortage of resources like water, land, and labour.

7.5.2 Farming techniques

FSL: GCSE Biology Revision "Modern Farming Techniques"

- The efficiency of food production can be improved by restricting energy transfer from food animals to the environment. This can be done by limiting their movement and by controlling the temperature of their surroundings.
- As these are the two main energy uses in respiration, reducing them means there is more energy available for growth.
- Some animals are fed high protein foods to increase growth.

Ethical concerns

- Animals are often raised in confined spaces, such as small cages.
- While this is more efficient, it can lead to stress and disease.
- 'Free range' farming is a more ethical approach, where animals are raised in large spaces and are allowed to roam free.
- (sidenote: When buying animal products, I would always go for free-range, not "battery" farmed as it's often called).

Other techniques

- Other techniques include:

Antibiotics in food: This reduces disease, however can cause antibiotic resistance.
Monocultures: This is when a single crop is grown in a field, to maximise food produced per area. This reduces biodiversity and often sucks nutrients from the soil, so something new should be grown every year in rotation.
Fertiliser use: This is the use of chemicals to increase the growth of plants. This can be done by adding nitrogen, phosphorus, and potassium to the soil. Runoff can occur from fertiliser use, polluting waterways and harming aquatic life.
Hedgerow removal: This is the removal of hedgerows, which are trees that grow in the shade of the surrounding land. This makes it easier to farm with machinery, but reduces biodiversity.

7.5.3 Sustainable fisheries

FSL: GCSE Biology Revision "Sustainable Fisheries"

- Fish stocks in the oceans are declining. It is important to maintain fish stocks at a level where breeding continues or certain species may disappear altogether in some areas.
- This is due to overfishing.
- Sustainable fisheries are those that maintain fish stocks so that there are a similar number of fish being born as there are being fished.
- Control of net size and the introduction of fishing quotas play important roles in conservation of fish stocks at a sustainable level.
- Larger gaps in fish nets mean that fewer, often just discarded, species will be caught which will help not to deplete populations of these species.
- Younger fish are more likely to be able to get through these gaps too, so they will survive and be able to reproduce.
- Fishing quotas are a way of controlling the amount of fish that can be caught in a given area. This is done by setting a limit on the amount of fish that can be caught in a given period of time.

7.5.4 Role of Biotechnology

FSL: GCSE Biology Revision "Role of Biotechnology"

- Modern biotechnology techniques enable large quantities of microorganisms to be cultured for food.
- It involves altering the make-up of organisms to make them more suitable for food production.

Mycroproteins

- The fungus Fusarium is useful for producing mycoprotein, a protein-rich food suitable for vegetarians. The fungus is grown on glucose syrup, in aerobic conditions, and the biomass is harvested and purified.
- They are grown in conditions with optimum pH and temperature in large fermenting vats.
- The fungus grows in the fermenter, is harvested, and finally purified, to produce mycoprotein.
- Ever had Quorn? no? well, it's that. I eat it all the time because my mum lmao (anyway...).

Production of Insulin

- A genetically modified bacterium produces human insulin. When harvested and purified, this is used to treat people with diabetes.
- The gene for insulin production is extracted from a human cell through the use of restrictive enzymes, which leave it with "sticky" ends of unpaired bases in DNA strands.
- A bacterial plasmid is cut by the same restriction enzyme leaving it with corresponding sticky ends.
- They are joined together by DNA ligase enzymes.
- The gene for human insulin is inserted into the DNA of bacteria by using a small circular piece of DNA (the plasmid).
- These genetically modified bacteria are then cultured in large fermenters where they reproduce rapidly, producing insulin.
- The insulin is then extracted, purified, and packaged for medical use.

Genetically modified crops

- GM (Genetically Modified) crops could provide more food or food with an improved nutritional value such as golden rice.
- Golden rice is a genetically modified rice that has been engineered to contain higher levels of vitamin A, the deficiency of which kills over half a million children each year.
- Some crops are engineered to be resistant to pests, diseases, and environmental stresses.
- This can provide greater yields and reduce the need for pesticides and herbicides.
- Selective breeding can also be used to achieve this, but to a lesser extent, by basically speeding up evolution and choosing exactly the traits that are desired.

Table I stole from BBC Bitesize

_{im so done with this topic, sorry}

	Natural selection	Selective breeding	Genetic engineering
Number of generations needed for change	Very many	Many	One
Human intervention	Not needed	Needed	Needed
Desired outcome known?	No	Yes	Yes
New species formed?	Yes	Eventually	No
Notes	This is the mechanism of change in Darwin's theory of evolution	This is how new varieties or breeds are usually produced	Genetic information can come from the same species or from a different one