Ecology is all about how living things interact with each...
GCSE Ecology Revision Questions









Ecosystems, Competition and Adaptations
Every ecosystem is like a massive community where living things interact with their surroundings. Abiotic factors are the non-living parts of the environment - things like temperature, light intensity, and soil pH that affect where organisms can survive.
Biotic factors are all the living components that influence each other. These include food availability, new predators showing up, or diseases spreading through populations. Plants compete for light, space, water, and minerals from the soil, whilst animals fight over territory, food, water, and mates.
Interdependence means species rely on each other for survival - remove one species and it creates a domino effect throughout the entire community. Organisms have developed three types of adaptations: structural (body features like shape or colour), behavioural (like migration patterns), and functional (internal processes like metabolism).
Key Point: Environmental changes from seasonal shifts, geographical factors, or human activity can dramatically affect where species can live and thrive.

Studying Organisms and Food Chains
Extremophiles are tough microorganisms that live in extreme conditions where most life couldn't survive. Scientists study organism distribution using quadrats (square frames) and transects (straight lines across habitats) to count and compare populations in different areas.
Producers like green plants and algae kick off every food chain by making glucose through photosynthesis. This glucose becomes their biomass - the building blocks of life. Food chains follow a simple pattern: Producers → Primary Consumers (herbivores) → Secondary Consumers (carnivores) → Tertiary Consumers.
Predator-prey relationships create natural cycles where populations rise and fall together. When there's lots of prey, predator numbers increase. As predators eat more prey, prey numbers drop, which then causes predator numbers to fall too.
Remember: Energy transfers between organisms when they eat each other, but materials like carbon and nitrogen get recycled through the environment to be used again and again.

Cycles and Decomposition
The carbon cycle keeps carbon moving between the atmosphere, living things, and the environment. Plants remove CO₂ during photosynthesis, animals release it through respiration, and decomposers break down dead organisms to return carbon to the soil and air.
The water cycle uses the sun's energy to evaporate water from seas, which condenses into clouds and falls as rain to provide fresh water for all life. It's a continuous loop that's been running for billions of years.
Decomposition breaks down dead organisms and waste, creating compost that acts as natural fertiliser. The rate of decay depends on temperature (warmer speeds it up), oxygen availability, water levels, and the number of decomposer organisms present.
Practical Tip: In the decay rate experiment, you'll use lipase enzyme to speed up the decomposition process and measure how temperature affects the rate using the formula: rate = 1000/time.

Environmental Changes and Biodiversity
Biodiversity - the variety of species in an ecosystem - keeps environments stable because different species depend on each other. However, human population growth is reducing biodiversity as we demand more resources and energy, taking materials from the environment faster than they can be replaced.
Human waste pollutes water, land, and air in different ways. Landfills leak toxic chemicals into waterways, pesticides damage soil and organisms, and industrial emissions create acid rain. Deforestation in tropical areas worsens climate change by reducing photosynthesis and releasing stored carbon when trees are burned.
Global warming results from increasing greenhouse gases like CO₂ and methane. This causes rising sea levels, flooding, habitat loss, and forces species to change their migration patterns or face extinction.
Action Point: Scientists create conservation programmes including breeding endangered species, protecting rare habitats, and encouraging recycling to minimise ecosystem damage - though these efforts face challenges from cost and economic pressures.

Trophic Levels and Energy Transfer
Trophic levels represent the different stages of food chains, with four main levels. Level one contains producers (plants and algae), level two has primary consumers (herbivores), level three includes secondary consumers (carnivores), and level four features tertiary consumers - the apex predators at the top.
Pyramids of biomass show how much living material exists at each trophic level. Producers only capture about 1% of available light energy, and approximately 10% of biomass transfers to each higher level. The rest gets lost through incomplete eating, excretion, and respiration.
Decomposers like bacteria and fungi break down dead organisms by secreting enzymes that turn complex materials into simple molecules they can absorb. This recycling process is essential for returning nutrients to the ecosystem.
Calculation Key: Biomass transfer efficiency = (biomass transferred to next level ÷ biomass at previous level) × 100

Food Security and Production
Food security means having enough food to feed everyone, but it's threatened by growing populations, changing diets in developed countries, new pests and diseases, environmental changes, and conflicts over resources.
Overfishing has caused fish stock declines, but solutions include fishing quotas (limits on catches) and using bigger mesh nets so young fish can escape to reach breeding age. Food production efficiency improves by restricting animal movement, controlling temperatures, and feeding high-protein diets - though these intensive methods raise disease spread and animal welfare concerns.
Biotechnology uses living organisms to create useful products. Mycoprotein from Fusarium fungus provides high-protein meat substitutes for vegetarians. Human insulin production involves inserting human genes into bacteria using restriction enzymes and plasmids.
Ethics Check: Genetic modification can create pest-resistant crops and improve nutrition (like vitamin A-enhanced golden rice), but critics argue we should tackle poverty and soil quality issues first rather than just modifying crops.


We thought you’d never ask...
Similar content
Most popular content: Ecology
3Ecology and Biodiversity Overview
Explore key concepts in ecology, including food chains, biodiversity, and the impact of human activities on ecosystems. This comprehensive summary covers essential topics such as GMOs, climate change, and conservation strategies, providing a clear understanding of ecological principles and their relevance to environmental science. Ideal for AQA Biology Paper 2 preparation.
Ecology: Sampling Techniques
Explore essential sampling methods in ecology, focusing on quadrats and transects for measuring population density and distribution. This practical guide covers step-by-step procedures for effective data collection and analysis, tailored for AQA Biology students.
Ecological Interactions Overview
Explore key concepts in ecology, including adaptations, food chains, biogeochemical cycles, and the roles of biotic and abiotic factors. This summary covers essential topics such as competition, interdependence, and decomposition processes, providing a comprehensive understanding for GCSE AQA students.
Most popular content in Biology
9Cell Biology and Cell structure
cell structures
The functions of subcellular structures - B1 Biology
Flashcards on the different functions of subcellular structures: cell membrane, nucleus, mitochondria, ribosomes, cytoplasm, permant vacuole, chloroplasts and cell wall.
1.cells Gcse biology question cards
combined science higher biology
AQA Biology: Key Concepts
Explore essential AQA Biology topics including Photosynthesis, Respiration, Homeostasis, Genetics, and Ecology. This comprehensive knowledge organizer covers key concepts such as energy transfer, hormonal control, and genetic variation, providing a solid foundation for your studies. Ideal for exam preparation and understanding biological processes.
Biology Paper 1 quiz
this is a simple quiz on key knowledge needed for paper 1
Types of cells
biology
A-Level Biology Year 1 Overview
Comprehensive summary of AQA A-Level Biology Year 1, covering key topics such as cellular structure, protein synthesis, immune response, gas exchange, and more. Ideal for exam preparation and understanding biological concepts. Includes detailed insights into cellular processes, biological classification, and the circulatory system.
biology paper 1
all notes
biology paper 1
these are some exam questions for biology paper which are more likely to come up in exams
Most popular content
9Sociology of Education Overview
Explore comprehensive A-Level Sociology notes on the education system, covering key theories, policies, and sociological perspectives. This resource includes insights on marketisation, gender roles, cultural deprivation, and educational inequalities, providing a thorough understanding of how education shapes social stratification and individual achievement. Ideal for exam preparation and in-depth study.
Sociology of Families: Comprehensive Revision
Dive into an extensive overview of family dynamics, perspectives, and patterns in sociology. This resource covers key concepts such as family diversity, gender roles, marriage, and the impact of social policies on family structures. Perfect for A-Level Sociology students preparing for Paper 2.
Criminology: Crime & Punishment Overview
Comprehensive mindmaps covering key concepts in the Crime and Punishment topic for WJEC Criminology Unit 4. This resource includes detailed insights into the Criminal Justice System, crime prevention strategies, sentencing models, and the roles of various agencies. Ideal for A-Level revision, ensuring you grasp essential theories and legislative processes to excel in your exams.
Comprehensive Crime & Deviance Overview
Explore an extensive revision of crime and deviance topics, including theories, types of crime, and the impact of media. This resource covers key concepts such as Marxism, functionalism, gender and crime, and the influence of globalization on criminal behavior. Ideal for students seeking a thorough understanding of criminology and its various theories. Type: Full Topic Revision.
Cell Biology and Cell structure
cell structures
WJEC Unit 4 Criminology
Criminology unit 4 detailed revision note
Sociological Theories Overview
Comprehensive revision of key sociological theories including Functionalism, Marxism, Feminism, and Interpretivism. Explore concepts like value freedom, identity formation, and the critique of social control. Ideal for AQA A-Level Sociology students preparing for exams. This summary covers essential theories and their implications in sociology, providing a clear understanding of each perspective.
The functions of subcellular structures - B1 Biology
Flashcards on the different functions of subcellular structures: cell membrane, nucleus, mitochondria, ribosomes, cytoplasm, permant vacuole, chloroplasts and cell wall.
1.cells Gcse biology question cards
combined science higher biology
Students love us — and so will you.
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
GCSE Ecology Revision Questions
Ecology is all about how living things interact with each other and their environment - think of it as nature's big web of connections. You'll discover how organisms compete, adapt, and depend on each other, plus learn about the impact...

Ecosystems, Competition and Adaptations
Every ecosystem is like a massive community where living things interact with their surroundings. Abiotic factors are the non-living parts of the environment - things like temperature, light intensity, and soil pH that affect where organisms can survive.
Biotic factors are all the living components that influence each other. These include food availability, new predators showing up, or diseases spreading through populations. Plants compete for light, space, water, and minerals from the soil, whilst animals fight over territory, food, water, and mates.
Interdependence means species rely on each other for survival - remove one species and it creates a domino effect throughout the entire community. Organisms have developed three types of adaptations: structural (body features like shape or colour), behavioural (like migration patterns), and functional (internal processes like metabolism).
Key Point: Environmental changes from seasonal shifts, geographical factors, or human activity can dramatically affect where species can live and thrive.

Studying Organisms and Food Chains
Extremophiles are tough microorganisms that live in extreme conditions where most life couldn't survive. Scientists study organism distribution using quadrats (square frames) and transects (straight lines across habitats) to count and compare populations in different areas.
Producers like green plants and algae kick off every food chain by making glucose through photosynthesis. This glucose becomes their biomass - the building blocks of life. Food chains follow a simple pattern: Producers → Primary Consumers (herbivores) → Secondary Consumers (carnivores) → Tertiary Consumers.
Predator-prey relationships create natural cycles where populations rise and fall together. When there's lots of prey, predator numbers increase. As predators eat more prey, prey numbers drop, which then causes predator numbers to fall too.
Remember: Energy transfers between organisms when they eat each other, but materials like carbon and nitrogen get recycled through the environment to be used again and again.

Cycles and Decomposition
The carbon cycle keeps carbon moving between the atmosphere, living things, and the environment. Plants remove CO₂ during photosynthesis, animals release it through respiration, and decomposers break down dead organisms to return carbon to the soil and air.
The water cycle uses the sun's energy to evaporate water from seas, which condenses into clouds and falls as rain to provide fresh water for all life. It's a continuous loop that's been running for billions of years.
Decomposition breaks down dead organisms and waste, creating compost that acts as natural fertiliser. The rate of decay depends on temperature (warmer speeds it up), oxygen availability, water levels, and the number of decomposer organisms present.
Practical Tip: In the decay rate experiment, you'll use lipase enzyme to speed up the decomposition process and measure how temperature affects the rate using the formula: rate = 1000/time.

Environmental Changes and Biodiversity
Biodiversity - the variety of species in an ecosystem - keeps environments stable because different species depend on each other. However, human population growth is reducing biodiversity as we demand more resources and energy, taking materials from the environment faster than they can be replaced.
Human waste pollutes water, land, and air in different ways. Landfills leak toxic chemicals into waterways, pesticides damage soil and organisms, and industrial emissions create acid rain. Deforestation in tropical areas worsens climate change by reducing photosynthesis and releasing stored carbon when trees are burned.
Global warming results from increasing greenhouse gases like CO₂ and methane. This causes rising sea levels, flooding, habitat loss, and forces species to change their migration patterns or face extinction.
Action Point: Scientists create conservation programmes including breeding endangered species, protecting rare habitats, and encouraging recycling to minimise ecosystem damage - though these efforts face challenges from cost and economic pressures.

Trophic Levels and Energy Transfer
Trophic levels represent the different stages of food chains, with four main levels. Level one contains producers (plants and algae), level two has primary consumers (herbivores), level three includes secondary consumers (carnivores), and level four features tertiary consumers - the apex predators at the top.
Pyramids of biomass show how much living material exists at each trophic level. Producers only capture about 1% of available light energy, and approximately 10% of biomass transfers to each higher level. The rest gets lost through incomplete eating, excretion, and respiration.
Decomposers like bacteria and fungi break down dead organisms by secreting enzymes that turn complex materials into simple molecules they can absorb. This recycling process is essential for returning nutrients to the ecosystem.
Calculation Key: Biomass transfer efficiency = (biomass transferred to next level ÷ biomass at previous level) × 100

Food Security and Production
Food security means having enough food to feed everyone, but it's threatened by growing populations, changing diets in developed countries, new pests and diseases, environmental changes, and conflicts over resources.
Overfishing has caused fish stock declines, but solutions include fishing quotas (limits on catches) and using bigger mesh nets so young fish can escape to reach breeding age. Food production efficiency improves by restricting animal movement, controlling temperatures, and feeding high-protein diets - though these intensive methods raise disease spread and animal welfare concerns.
Biotechnology uses living organisms to create useful products. Mycoprotein from Fusarium fungus provides high-protein meat substitutes for vegetarians. Human insulin production involves inserting human genes into bacteria using restriction enzymes and plasmids.
Ethics Check: Genetic modification can create pest-resistant crops and improve nutrition (like vitamin A-enhanced golden rice), but critics argue we should tackle poverty and soil quality issues first rather than just modifying crops.


We thought you’d never ask...
Similar content
Most popular content: Ecology
3Ecology and Biodiversity Overview
Explore key concepts in ecology, including food chains, biodiversity, and the impact of human activities on ecosystems. This comprehensive summary covers essential topics such as GMOs, climate change, and conservation strategies, providing a clear understanding of ecological principles and their relevance to environmental science. Ideal for AQA Biology Paper 2 preparation.
Ecology: Sampling Techniques
Explore essential sampling methods in ecology, focusing on quadrats and transects for measuring population density and distribution. This practical guide covers step-by-step procedures for effective data collection and analysis, tailored for AQA Biology students.
Ecological Interactions Overview
Explore key concepts in ecology, including adaptations, food chains, biogeochemical cycles, and the roles of biotic and abiotic factors. This summary covers essential topics such as competition, interdependence, and decomposition processes, providing a comprehensive understanding for GCSE AQA students.
Most popular content in Biology
9Cell Biology and Cell structure
cell structures
The functions of subcellular structures - B1 Biology
Flashcards on the different functions of subcellular structures: cell membrane, nucleus, mitochondria, ribosomes, cytoplasm, permant vacuole, chloroplasts and cell wall.
1.cells Gcse biology question cards
combined science higher biology
AQA Biology: Key Concepts
Explore essential AQA Biology topics including Photosynthesis, Respiration, Homeostasis, Genetics, and Ecology. This comprehensive knowledge organizer covers key concepts such as energy transfer, hormonal control, and genetic variation, providing a solid foundation for your studies. Ideal for exam preparation and understanding biological processes.
Biology Paper 1 quiz
this is a simple quiz on key knowledge needed for paper 1
Types of cells
biology
A-Level Biology Year 1 Overview
Comprehensive summary of AQA A-Level Biology Year 1, covering key topics such as cellular structure, protein synthesis, immune response, gas exchange, and more. Ideal for exam preparation and understanding biological concepts. Includes detailed insights into cellular processes, biological classification, and the circulatory system.
biology paper 1
all notes
biology paper 1
these are some exam questions for biology paper which are more likely to come up in exams
Most popular content
9Sociology of Education Overview
Explore comprehensive A-Level Sociology notes on the education system, covering key theories, policies, and sociological perspectives. This resource includes insights on marketisation, gender roles, cultural deprivation, and educational inequalities, providing a thorough understanding of how education shapes social stratification and individual achievement. Ideal for exam preparation and in-depth study.
Sociology of Families: Comprehensive Revision
Dive into an extensive overview of family dynamics, perspectives, and patterns in sociology. This resource covers key concepts such as family diversity, gender roles, marriage, and the impact of social policies on family structures. Perfect for A-Level Sociology students preparing for Paper 2.
Criminology: Crime & Punishment Overview
Comprehensive mindmaps covering key concepts in the Crime and Punishment topic for WJEC Criminology Unit 4. This resource includes detailed insights into the Criminal Justice System, crime prevention strategies, sentencing models, and the roles of various agencies. Ideal for A-Level revision, ensuring you grasp essential theories and legislative processes to excel in your exams.
Comprehensive Crime & Deviance Overview
Explore an extensive revision of crime and deviance topics, including theories, types of crime, and the impact of media. This resource covers key concepts such as Marxism, functionalism, gender and crime, and the influence of globalization on criminal behavior. Ideal for students seeking a thorough understanding of criminology and its various theories. Type: Full Topic Revision.
Cell Biology and Cell structure
cell structures
WJEC Unit 4 Criminology
Criminology unit 4 detailed revision note
Sociological Theories Overview
Comprehensive revision of key sociological theories including Functionalism, Marxism, Feminism, and Interpretivism. Explore concepts like value freedom, identity formation, and the critique of social control. Ideal for AQA A-Level Sociology students preparing for exams. This summary covers essential theories and their implications in sociology, providing a clear understanding of each perspective.
The functions of subcellular structures - B1 Biology
Flashcards on the different functions of subcellular structures: cell membrane, nucleus, mitochondria, ribosomes, cytoplasm, permant vacuole, chloroplasts and cell wall.
1.cells Gcse biology question cards
combined science higher biology
Students love us — and so will you.
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.