Human Influences on Ecosystems
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Food supply and habitat destruction
SubtopicFood supply and habitat destruction under Human Influences on Ecosystems for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
In the context of habitat destruction, what does the term 'biodiversity' refer to?
A.The total mass of all living organisms in a specific ecosystem.
B.The number of different species living in a particular area.
C.The speed at which energy flows through a food web.
D.The amount of carbon dioxide absorbed by a forest in one year.
- 2.
Which of the following is a major reason for the destruction of tropical rainforests?
A.To increase the global rate of photosynthesis.
B.To provide land for cattle ranching and palm oil plantations.
C.To reduce the frequency of flooding in lower river basins.
D.To protect endangered species from natural predators.
- 3.
The diagram shows a simplified food chain in a farmland ecosystem. If a farmer applies a non-specific insecticide that eliminates the insect population, what is the most likely immediate effect on the other organisms?
A.The bird population will decrease due to a lack of food.
B.The hawk population will increase as they find alternative food sources.
C.The crop yield will decrease because there are no insects to eat them.
D.The birds will start eating the crops to survive.
Download the worksheet for Human Influences on Ecosystems - Food supply and habitat destruction to practice offline. It includes additional chapter-level practice questions.
Pollution (Greenhouse effect)
SubtopicPollution (Greenhouse effect) under Human Influences on Ecosystems for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
Greenhouse gases trap heat in the atmosphere by absorbing which type of radiation emitted from the Earth's surface?
A.Ultraviolet radiation
B.Infrared radiation
C.Visible light
D.Microwave radiation
- 2.
Which human activity is a significant source of methane () emissions?
A.Nuclear power generation
B.Reforestation projects
C.Rice paddy cultivation and cattle farming
D.Production of chlorofluorocarbons (CFCs)
- 3.
What is the primary role of the natural greenhouse effect in Earth's biosphere?
A.To reflect all incoming solar radiation back into space
B.To maintain a global average temperature that supports life
C.To provide the oxygen necessary for aerobic respiration
D.To protect the Earth from high-energy -ray radiation
Download the worksheet for Human Influences on Ecosystems - Pollution (Greenhouse effect) to practice offline. It includes additional chapter-level practice questions.
Conservation
SubtopicConservation under Human Influences on Ecosystems for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
Which human activity is the most significant contributor to the current increase in the global 'greenhouse effect'?
A.Overfishing in international waters.
B.The combustion of fossil fuels for transport and industry.
C.The use of nuclear power for electricity generation.
D.The planting of large-scale monocultures.
- 2.
What is the primary role of a 'seed bank' in plant conservation?
A.To sell genetically modified seeds to local farmers.
B.To create new species of plants through artificial selection.
C.To provide a backup of plant genetic diversity to prevent extinction.
D.To store food for animals during the winter months.
- 3.
Which of these is considered a non-renewable resource that conservation efforts aim to reduce the dependency on?
A.Fossil fuels
B.Solar energy
C.Geothermal heat
D.Biomass from managed forests
Download the worksheet for Human Influences on Ecosystems - Conservation to practice offline. It includes additional chapter-level practice questions.