biological factors affecting food security

Question 1

arable farming

definition

Answer 1

When crops are grown.

Question 2

bioethanol

definition

Answer 2

Ethanol that has been produced from crops. Bioethanol is an example of a biofuel.

Question 3

compost

definition

Answer 3

Decayed organic matter which can be used as a plant fertiliser.

Question 4

eutrophication

definition

Answer 4

‘Hyper-nutrition’ resulting from fertiliser pollution of aquatic ecosystems.

Question 5

What was the industrial revolution?

Answer 5

The process that transformed manufacturing from handmade to machine-made, mass-produced goods using water, steam and coal power transported by canal, rail and steamship. Britain was the first country to have an Industrial Revolution.

Question 6

intensive farming

definition

Answer 6

Farming methods that usually involve monoculture (growing one crop) and using pesticides and fertilisers to improve crop yield.

Question 7

manure

definition

Answer 7

Animal dung (solid waste) used as fertiliser.

Question 8

monocultre

definition

Answer 8

Growing one type of crop.

Question 9

non-renewable

definition

Answer 9

A resource that cannot be replaced when it is used up, such as oil, natural gas or coal.

Question 10

over-fishing

definition

Answer 10

To catch fish in such high numbers that species struggle to survive.

Question 11

pesticide

definition

Answer 11

A chemical used to kill pests, such as the potato cyst nematode which is a pest that destroys potato crops.

Question 12

sustainability

definition

Answer 12

The ability to keep something going over time without harming people or the environment.

Question 13

What is the theory of evolution?

Answer 13

A theory put forward by Charles Darwin that all living creatures that exist today, including human beings, have evolved over a period of millions of years from more primitive life forms.

Question 14

What is food security?

Answer 14

Food security is a measure of the availability of food required to support people of a household, region, country or any specified area. It is a measure of how much food there is, if it is of suitable quality and whether people can access it.

Question 15

Food security is reduced by:

Answer 15

• The increase in human population, as birth rates are increasing and many people have better access to medical care.
• Changing diets eg people starting to eat more meat in newly developed countries like China. This means that food resources are transported to be sold from areas which need them, especially meat and fish.
• New pests and pathogens that attack crops and farm animals.
• Environmental changes such as global warming.
• Increased costs of farming.
• Armed conflicts.

Question 16

Intensive farming

overview

Answer 16

Intensive farming uses machines, fertilisers, man-power and high-yield crops to maximise the amount of food produced. Farmers growing arable crops often specialise in growing only one crop to maximise their profits. This is called monoculture. It can quickly reduce key nutrients in the soil and lowers biodiversity.

Question 17

Intensive farming

Hedgerows

Answer 17

Hedgerows have been removed from many fields to make them bigger and easier to tend to by big machines. This also reduces biodiversity. Crops are often sown, treated and harvested by machines which create pollution, and fertilisers are added to fields in larger amounts which can cause eutrophication.

Question 18

Intensive farming

Livestock

Answer 18

Intensive farming can also mean keeping livestock in smaller pens with regulated temperatures. This reduces the energy they need for movement and temperature regulation and so maximises their size and yield. Some animals are fed high protein foods to increase their growth. They are often fed antibiotics in their food to prevent diseases. Many scientists think this is leading to antibiotic resistance in bacteria.

Question 19

Advantages of intensive farming practices

Answer 19

• Higher yields
• Cheaper food for the consumer
• More efficient use of food
• Quality control easier

Question 20

Disadvantages of intensive farming practices

Answer 20

• Reduction in biodiversity
• Creates pollution
• Risk of antibiotic resistance
• Considered unethical by some people

Question 21

Why many people object to intensive farming

Answer 21

Many people object to intensive farming because it reduces biodiversity and increases pollution. More recently some farms have become organic to address this.

Question 22

Organic farming

Answer 22

Organic farmers do not use machines to the same extent as intensive farming. They do not apply pesticides to their crops and use natural fertilisers such as compost and manure. They rotate their crops to avoid monoculture.

Question 23

Intensive farming of animals

Answer 23

The demand for more meat has resulted in increased intensive farming of animals such as cattle, pigs and chickens. This has an impact on food security because animal farming wastes more energy because the food chain is longer. It is much more efficient to grow crops so more people can be fed per area of land. In addition, farmed animals are often fed crops which could be consumed by humans.

Question 24

Farming techniques

Negative impact of pathogens and pests

Answer 24

Pathogens including bacteria, fungi and viruses may infect the crops or farm animals and will reduce the yield of crops and reduce the food availability for the human population. New pathogens may reduce yields dramatically as the crops or animals may not be resistant. New diseases may lead to crop failure and reduced food production. Also new pests such as insects may damage the growth of crops, reducing yield and food security.

Question 25

Sustainability and farming

Answer 25

Sustainability means maintaining the needs of the human population into the future. This includes food security and fuel for vehicles and industry. Fuels such as diesel and petrol made from crude oil are non-renewable and are running out. An alternative fuel is biofuel such as bioethanol which is made by fermenting sugar from corn or sugar cane. Therefore these biofuel crops provide a renewable fuel. They have a negative impact though, as they are often grown on land which could be used for growing crops for food.

Question 26

Farming techniques

Cost of agricultural inputs

Answer 26

Farming is expensive in terms of land costs, machinery, fuel and fertilisers. As costs increase, many farmers find it too expensive to continue farming so farms shut down and food production stops. This has a negative impact on food security.

Question 27

Biofuel

definition

Answer 27

A type of energy source derived from renewable plant and animal materials, eg ethanol (often made from corn in the United States and sugarcane in Brazil), biodiesel (vegetable oils and liquid animal fats) and biogas (methane from animal manure).

Question 28

arable farming

definition

Answer 28

When crops are grown.

Question 29

compost

definiton

Answer 29

Decayed organic matter which can be used as a plant fertiliser

Question 30

Pathogen

definition

Answer 30

Microorganism that causes disease.

Question 31

effect of sustainable fisheries on number of fish

Answer 31

Sustainable fisheries do not reduce the overall number of fish, because the number of fish that are caught and killed does not ever exceed the birth of new fish.

Question 32

Overfishing

Answer 32

At one point we thought that we could remove as many fish as we wanted from the oceans without any consequence. During this period, we drastically overfished some of our oceans and seas and reduced some populations to critically low numbers.

Question 33

Result of overfishing

Answer 33

Some scientists think that as much as 85% of the world’s fish populations have been overfished. Common examples are cod in the North Sea and sole in the Irish Sea and English Channel. Overfishing can cause a critical point in populations that means certain species cannot ever recover and will become extinct.

Question 34

Addressing overfishing

Answer 34

To address overfishing many countries are adopting a more sustainable strategy for fishing and have introduced fishing quotas which limit the amount of fish that can be caught and killed from specific species. The size of the gaps in fishing nets has also been increased to ensure that juvenile fish can reach reproductive maturity and have offspring before being caught.

These practices have meant that many fish populations are now recovering.

Question 35

Positive effects of the greenhouse effect

Answer 35

Without the greenhouse effect the mean temperature on Earth would be -18°C and there would be very little or no life. So the greenhouse effect itself is a good thing. The greenhouse effect traps some of the energy from the Sun, which keeps our planet at a suitable temperature for life.

Question 36

Problem with our increased release of greenhouse gases

Answer 36

The problem is that our increased release of greenhouse gases is causing an increase in the greenhouse effect called the enhanced greenhouse effect. This is leading to global warming.

Question 37

Carbon dioxide increase since the industrial revolution

Answer 37

Carbon dioxide, water vapour and methane are amongst the most common greenhouse gases. Since the start of the Industrial Revolution in about 1750 the levels of carbon dioxide have increased by 40%.

Question 38

Global warming

overview

Answer 38

Global warming is the increase in the mean temperature of the Earth. The ten hottest years since records began have been in the last 30 years. The mean increase in the last 100 years has been less than 1°C. This might seem small, but is enough to have devastating consequences on many species in different parts of the world.

Question 39

Global warming

Relationship between carbon dioxide and the earth’s mean temperature

Answer 39

As the percentage of carbon dioxide in our atmosphere has increased so has the Earth’s mean temperature

Question 40

The consequences of global warming are:

Answer 40

• melting of the polar ice caps
• the rise in sea level may one day threaten many cities such as London, New York and Amsterdam
• weather patterns will change with more unusual weather
• animals will migrate towards the poles to find habitats with suitable temperatures
• tropical diseases may become more common in other regions, such as Europe
• change in distribution of pests that attack crops, which will have an impact on food security in some areas
• many species will become extinct

Question 41

Monoculture is the growing of what?

Answer 41

Monoculture is the growing of one crop per field. It is more effective and profitable for the farmer.

Question 42

What is a pathogen?

Answer 42

A disease causing organism

Question 43

What can the overuse of fertilisers in intensive farming lead to?

Answer 43

Eutrophication

Question 44

Why do farmers keep cattle in small pens?

Answer 44

To reduce energy wasted in movement and increase yield

Question 45

How have some countries tried to preserve fish stocks?

Answer 45

Quotas

Some countries have tried to preserve fish stocks by the introduction of quotas. This will restrict the amount of fishing and protect fish species.

Question 46

What types of fishing nets have been introduced to protect fish?

Answer 46

Fishing nets have been introduced with larger gaps. This means that younger, smaller fish can have offspring before being caught.

Question 47

What are the consequences of global warming?

Answer 47

Melting of the polar ice caps and increased sea levels

Question 48

An increase in the greenhouse gas methane will do what to the temperature of the earth?

Answer 48

Increase