GCSE Biology revision

Waste management

Biodiversity and the effect of human interaction on ecosystems

AQA 4.1.1.1

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AQA student objectives

Learning pathway

All · Most · Some

ALL 🎯

Identify and describe Human Population Growth, Resource Use and Population Pressure and Forms of Pollution in the context of waste management.

MOST 🎯🎯

Explain the relationships between Human Population Growth, Resource Use and Population Pressure and Forms of Pollution and how they contribute to waste management.

SOME 🎯🎯🎯

Apply and analyse knowledge of Human Population Growth, Resource Use and Population Pressure and Forms of Pollution to interpret unfamiliar information about waste management.

Revision summary

Key knowledge

Read on screen, then print for Cornell-style active revision.

Human Population Growth

The human population has increased exponentially over time, with countries such as India and China each reaching populations of around one billion.
Each year, the global population increases by approximately 75 million people.
Population growth has occurred due to lower infant mortality rates, higher life expectancy, better healthcare, and improved food production and water availability.
Cultural factors, such as religious views on contraception and preferences for large families, also contribute to population growth.

1. Human Population GrowthAQA

Notes

The human population has increased exponentially over time, with countries such as India and China each reaching populations of around one billion.
Each year, the global population increases by approximately 75 million people.
Population growth has occurred due to lower infant mortality rates, higher life expectancy, better healthcare, and improved food production and water availability.
Cultural factors, such as religious views on contraception and preferences for large families, also contribute to population growth.

Resource Use and Population Pressure

As the population grows, more resources are consumed and more energy is required to meet demand.
Increased population leads to greater use of fossil fuels and a rise in the amount of waste produced.
China introduced the controversial one-child policy in response to resources not meeting the demands of its rapidly growing population.
Scientists warn that if resource consumption continues to outpace supply, the entire planet could face a similar crisis.

2. Resource Use and Population PressureAQA

Notes

As the population grows, more resources are consumed and more energy is required to meet demand.
Increased population leads to greater use of fossil fuels and a rise in the amount of waste produced.
China introduced the controversial one-child policy in response to resources not meeting the demands of its rapidly growing population.
Scientists warn that if resource consumption continues to outpace supply, the entire planet could face a similar crisis.

Forms of Pollution

Pollution caused by human activity can be found in water, in the air, and on land.
As the human population grows, the volume of waste produced increases, leading to greater levels of pollution across all environments.
Pollution reduces species diversity, making ecosystems far less stable and threatening overall biodiversity.

Water Pollution and Fertiliser Run-off

When farmers apply fertilisers to their fields, heavy rainfall can wash these nutrients into nearby rivers, lakes, and streams — a process known as run-off.
Fertilisers cause a spike in nitrogen, ammonia, and other nutrients in bodies of water, which is toxic to many aquatic organisms.
The excess nutrients cause aquatic plants and algae to grow very rapidly and densely, a process that ultimately removes oxygen from the water.
The removal of oxygen leads to the large-scale die-off of aquatic organisms, including eventually the plants themselves.

4. Water Pollution and Fertiliser Run-offAQA

Notes

When farmers apply fertilisers to their fields, heavy rainfall can wash these nutrients into nearby rivers, lakes, and streams — a process known as run-off.
Fertilisers cause a spike in nitrogen, ammonia, and other nutrients in bodies of water, which is toxic to many aquatic organisms.
The excess nutrients cause aquatic plants and algae to grow very rapidly and densely, a process that ultimately removes oxygen from the water.
The removal of oxygen leads to the large-scale die-off of aquatic organisms, including eventually the plants themselves.

Eutrophication

Eutrophication is the process by which excess nutrients from fertilisers enter a body of water, triggering a chain of events that devastates aquatic ecosystems.
The sequence of eutrophication is: fertiliser run-off nutrient spike in water rapid algal and plant growth oxygen depletion death of aquatic organisms.
Eutrophication is a key exam topic and understanding the step-by-step process can earn you several marks in a question.

5. EutrophicationAQA

Notes

Eutrophication is the process by which excess nutrients from fertilisers enter a body of water, triggering a chain of events that devastates aquatic ecosystems.
The sequence of eutrophication is: fertiliser run-off nutrient spike in water rapid algal and plant growth oxygen depletion death of aquatic organisms.
Eutrophication is a key exam topic and understanding the step-by-step process can earn you several marks in a question.

Sewage and Water Contamination

In some parts of the world, untreated human waste (sewage) can leak into bodies of water, contributing to water pollution.
Sewage contamination of water supplies can cause severe illnesses such as cholera, posing a serious public health risk.

Air Pollution

Burning fossil fuels releases sulfur dioxide and carbon dioxide into the atmosphere, both of which are greenhouse gases that contribute to global warming.
Sulfur dioxide and carbon dioxide can combine with water in clouds to form acid rain, which damages plants, erodes monuments, and acidifies bodies of water.
High levels of air pollution produce harmful smoke, which can cause significant damage to the lungs of people living in heavily polluted urban areas.

7. Air PollutionAQA

Notes

Burning fossil fuels releases sulfur dioxide and carbon dioxide into the atmosphere, both of which are greenhouse gases that contribute to global warming.
Sulfur dioxide and carbon dioxide can combine with water in clouds to form acid rain, which damages plants, erodes monuments, and acidifies bodies of water.
High levels of air pollution produce harmful smoke, which can cause significant damage to the lungs of people living in heavily polluted urban areas.

Land Pollution and Landfill

Much of the waste produced by humans is disposed of in landfill sites, which can cause land pollution.
Hazardous materials such as batteries must not be placed in standard landfill, as their acid can leak out and contaminate the surrounding land.
Land pollution from waste disposal contributes to the destruction of habitats and a reduction in biodiversity.

8. Land Pollution and LandfillAQA

Notes

Much of the waste produced by humans is disposed of in landfill sites, which can cause land pollution.
Hazardous materials such as batteries must not be placed in standard landfill, as their acid can leak out and contaminate the surrounding land.
Land pollution from waste disposal contributes to the destruction of habitats and a reduction in biodiversity.

Impact on Biodiversity

Human-generated pollution — whether in water, air, or on land — has a damaging effect on biodiversity by reducing species diversity.
A reduction in species diversity makes ecosystems less stable and less resilient to environmental change.
Increasing and protecting biodiversity is essential for maintaining healthy, balanced ecosystems.

9. Impact on BiodiversityAQA

Notes

Human-generated pollution — whether in water, air, or on land — has a damaging effect on biodiversity by reducing species diversity.
A reduction in species diversity makes ecosystems less stable and less resilient to environmental change.
Increasing and protecting biodiversity is essential for maintaining healthy, balanced ecosystems.