Ecology | AQA GCSE Combined Science Trilogy Biology, Higher tier (8464)

Ecology

140 questions
11 subtopics
Biology Paper 2
Biology Paper 2

Ecology is examined in Biology Paper 2.

It covers levels of organisation in an ecosystem, and what organisms need, competition, interdependence and stable communities, abiotic factors, biotic factors, adaptations, producers, food chains and sampling with quadrats and transects, predators, prey and measuring population size, how materials are cycled, waste management and biodiversity, land use, deforestation and global warming and maintaining biodiversity.

Sample questions from Ecology

Answer each one closed book first, then open the answer.

Levels of organisation in an ecosystem, and what organisms need

What is an ecosystem?

Show the answer
The interaction of a community of living organisms with the non-living parts of their environment.
Competition, interdependence and stable communities

Why do plants compete for mineral ions?

Show the answer
They need mineral ions such as nitrate from the soil to make the proteins needed for growth.
Abiotic factors

Why is the direction of the wind, as well as its strength, an abiotic factor?

Show the answer
A steady wind from one direction dries and damages one side of a plant, so growth is lopsided and exposed sides support fewer plants.
Biotic factors

Grey squirrels are introduced into a wood containing red squirrels. Explain what may happen to the red squirrel population.

Show the answer
Grey squirrels compete for the same food and shelter and carry a disease the reds cannot resist, so red squirrel numbers fall.
Adaptations

What is a functional adaptation?

Show the answer
A feature of the way an organism's body works, such as producing very concentrated urine or slowing its metabolism.
Producers, food chains and sampling with quadrats and transects

What do the arrows in a food chain represent?

Show the answer
The transfer of biomass from the organism that is eaten to the organism that eats it.
Predators, prey and measuring population size

What is prey?

Show the answer
An animal that is killed and eaten by a predator.
How materials are cycled

Which process removes carbon dioxide from the atmosphere, and which two processes return it?

Show the answer
Photosynthesis removes it, while respiration and combustion return it.

The 11 subtopics

One subtopic is one session. Work down the list.

Subtopic	What it covers	Questions
Levels of organisation in an ecosystem, and what organisms need	Population, community, habitat and ecosystem, biotic and abiotic parts, what plants and animals must obtain to survive, and competition and adaptation in rock pools, deserts and streams.	12
Competition, interdependence and stable communities	What plants and animals compete for, with seedlings under trees and fighting deer, interdependence and what species depend on each other for, stable communities, the effects of losing bees or a single species, and reading producers and competition from tables.	12
Abiotic factors	The seven abiotic factors, dissolved oxygen in water, soil pH and minerals, wind direction, and how moisture, warming, acid rain, shelter and light change a community.	12
Biotic factors	Food availability, new predators, new pathogens and competition as biotic factors, with red and grey squirrels, poor acorn crops, island prey, lost plant species and diseased ash trees, and interpreting population data on introduced species and disease.	12
Adaptations	Structural, behavioural and functional adaptations, extremophiles such as deep sea vent bacteria and their enzymes, and examples including whale blubber, camel urine, Arctic fox ears and cactus spines and stems.	12
Producers, food chains and sampling with quadrats and transects	Producers and biomass, why a producer starts every food chain and what the arrows mean, quadrats and transects, distribution against abundance, and the mean, median and mode of counts.	13
Predators, prey and measuring population size	Primary, secondary and tertiary consumers, predators and prey and their cycling numbers, estimating a field's dandelions with random quadrats, and using a transect along a footpath.	13
How materials are cycled	Why materials must be recycled, the carbon cycle through photosynthesis, respiration, combustion and decomposers, the water cycle through evaporation, condensation and precipitation, and the role of microorganisms in returning carbon dioxide and mineral ions.	13
Waste management and biodiversity	Why a growing population and rising living standards produce more waste, sources of water, air and land pollution, how fertiliser, acid rain and toxic chemicals damage ecosystems, and what biodiversity is, why it makes ecosystems stable and how human activity has reduced it.	16
Land use, deforestation and global warming	Land lost to building, quarrying, farming and waste, peat bog destruction and the carbon dioxide it releases, tropical deforestation for cattle, rice and biofuels, carbon dioxide and methane in global warming, and its effects on species distribution and sea levels.	13
Maintaining biodiversity	Breeding programmes, habitat protection, field margins and hedgerows, recycling and cutting deforestation and carbon dioxide emissions, negative and positive human interactions with ecosystems, and the conflicts that conservation programmes can cause.	12

Ecology is 140 of the 1,080 questions in the guide.Get the guide, £7

How the guide is worked

Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.

Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.

Read the full method, the return schedule and the research behind it.