Your GCSE biology revision just got easier! This comprehensive guide... Show more
SociologySign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
148
•
13 Dec 2025
•
Essential Biology Terms for GCSE Success
Miriam
@mm_16
1 / 10
Cell Biology Fundamentals
Ever wondered how your body works at the tiniest level? Cell biology is where it all starts, and mastering these terms will give you a solid foundation for everything else in biology.
Cells are the basic building blocks of life, and they come in two main types. Eukaryotic cells (found in plants and animals) have a nucleus that controls everything, whilst prokaryotic cells (bacteria) don't have one. Inside these cells, you'll find organelles - specialised structures like mitochondria (where respiration happens) and chloroplasts (where photosynthesis occurs in plants).
Movement is crucial for cells to survive. Diffusion spreads particles from high to low concentration, osmosis moves water through membranes, and active transport uses energy to move substances against the concentration gradient. Think of it like swimming upstream - it takes effort!
Cell division through mitosis creates identical cells for growth and repair, whilst stem cells are the body's repair kit, able to become any specialised cell type. Understanding how these processes work together will help you tackle more complex biology topics with confidence.
Key Tip: Remember that active transport is the only process that requires energy - it's going against the natural flow!
Organisation and Disease
Your body is brilliantly organised, working like a well-oiled machine from cells to tissues to organs to organ systems. It's this organisation that keeps you alive and healthy every single day.
Your heart pumps blood through different vessels: arteries carry blood away from the heart at high pressure, veins bring it back at low pressure, and tiny capillaries allow exchange of materials. The aorta and pulmonary artery are your major highways, moving oxygenated and deoxygenated blood where they need to go.
Enzymes are your body's speed-up tools - biological catalysts that make reactions happen faster. Amylase breaks down carbohydrates, protease tackles proteins, and lipase handles fats. The lock and key hypothesis explains how enzymes work - substrates must fit perfectly into the enzyme's active site.
Disease comes in two forms: communicable diseases spread between people, whilst non-communicable diseases like cancer don't. Malignant tumours are the dangerous ones that spread, whilst benign tumours stay put. Understanding these differences helps you make sense of how different treatments work.
Key Tip: Think of enzymes like keys - each one only fits specific locks (substrates), and temperature changes can bend the key!
Plant Transport and Heart Health
Plants have their own transport systems that work differently from animals but are just as important. Xylem carries water and minerals up from roots to leaves, whilst phloem moves sugars around the plant through translocation.
Palisade mesophyll tissue is where most photosynthesis happens in leaves - it's packed with chloroplasts to catch maximum light. Spongy mesophyll handles gas exchange, allowing carbon dioxide in and oxygen out. Transpiration is like plant sweating - water evaporates from leaves, creating a pull that draws more water up through the plant.
Heart disease is a major health concern you should understand. Coronary heart disease occurs when fatty deposits block arteries supplying the heart muscle. Doctors can treat this by inserting stents to keep arteries open or prescribing statins to lower cholesterol levels.
Understanding risk factors helps you make informed choices about your health. Some you can't change (like genetics), but others like diet, exercise, and smoking are completely within your control.
Key Tip: Plants don't have hearts, but transpiration creates a powerful suction that can pull water up the tallest trees!
Infection and Response
Your body faces constant attack from pathogens - microorganisms that cause infectious disease - but your immune system is ready for battle. Understanding how infections work and how we fight them is crucial for your health and your exams.
Communicable diseases spread between people and include serious conditions like measles (viral), salmonella (bacterial), and malaria (protist). Each pathogen type requires different treatments - antibiotics kill bacteria but are useless against viruses.
Vaccination is one of medicine's greatest victories, introducing dead or inactive pathogens to train your white blood cells to recognise and fight real infections. Your body's non-specific defences like skin and stomach acid provide the first line of protection.
Clinical drug testing ensures medicines are safe and effective through rigorous stages. Preclinical testing uses cells and animals, followed by double blind trials where neither patients nor researchers know who gets the real drug versus a placebo. This prevents bias and ensures reliable results.
Key Tip: Remember that antibiotics only work on bacteria - taking them for viral infections like colds is pointless and can lead to resistance!
Bioenergetics and Homeostasis
Energy drives everything in biology, and understanding bioenergetics explains how organisms power their lives. Cellular respiration releases energy from glucose - aerobic respiration uses oxygen whilst anaerobic respiration doesn't.
Photosynthesis captures light energy to make glucose, and several factors can limit its rate. Limiting factors include light intensity, carbon dioxide concentration, and temperature. The inverse square law explains how light intensity decreases with distance - double the distance, quarter the intensity.
Homeostasis keeps your internal environment stable despite external changes. It's like your body's thermostat, constantly monitoring and adjusting conditions. Coordination centres like your brain process information from receptors and send signals to effectors that make changes.
Key hormones control different processes: insulin and glucagon regulate blood sugar, adrenaline prepares you for emergencies, and ADH controls water balance in your kidneys. Negative feedback cycles reverse changes to maintain balance - when blood sugar rises, insulin brings it down.
Key Tip: Think of homeostasis like driving a car - you constantly make small adjustments to stay on course rather than dramatic steering changes!
Reproduction and Plant Responses
Your body's reproductive system is controlled by carefully balanced hormones that work in cycles. FSH triggers egg maturation, LH causes egg release, and oestrogen prepares the uterus lining. Understanding these interactions explains both natural fertility and contraception methods.
Modern medicine offers solutions for fertility problems through IVF (in vitro fertilisation), where eggs and sperm meet outside the body before embryo transfer. Embryo screening can detect genetic conditions before implantation.
Plants respond to their environment through growth movements called tropisms. Phototropism makes shoots grow towards light, whilst geotropism (or gravitropism) makes roots grow down and shoots grow up. Plant hormones like auxins, gibberellins, and ethene control these responses.
Your sensory systems detect environmental changes. Reflex actions provide rapid, automatic responses to danger - like pulling your hand from a hot surface before you consciously feel pain. The central nervous system coordinates these responses through the brain and spinal cord.
Key Tip: Plant hormones work differently from animal hormones - they're made in one place but can affect growth throughout the entire plant!
Inheritance and DNA
Your DNA contains the blueprint for life, wound into a double helix structure carrying genetic information in genes. These genes come in different versions called alleles - some dominant (always expressed) and others recessive (only expressed when you have two copies).
Chromosomes package your DNA, and humans have 23 pairs. Sex chromosomes determine gender - XY for males, XX for females. During reproduction, meiosis creates gametes with half the usual chromosome number, restored during fertilisation.
Understanding inheritance patterns helps predict offspring characteristics. Homozygous individuals have identical alleles (like AA or aa), whilst heterozygous individuals have different alleles (like Aa). Punnett squares help calculate the probability of different outcomes.
Modern genetics involves genetic engineering - inserting useful genes from one organism into another. GM crops resist pests or herbicides, whilst gene therapy treats genetic disorders. Selective breeding has been used for thousands of years to develop crops and livestock with desirable traits.
Key Tip: Remember that genotype is what genes you have, but phenotype is what you actually look like - environment can influence how genes are expressed!
Evolution and Classification
Evolution explains how species change over time through natural selection - Charles Darwin's revolutionary idea that organisms with advantageous traits survive and reproduce more successfully. Mutations create genetic variants, and environmental pressures determine which survive.
Fossils provide evidence for evolution, showing how organisms changed over millions of years. Sometimes species become extinct when they can't adapt fast enough to changing conditions. New species form through speciation when populations become isolated and evolve differently.
Scientists classify organisms using the binomial system - each species gets two names (genus and species). The traditional Linnaean system groups organisms into kingdom, phylum, class, order, family, genus, and species. The modern three-domain system recognises Archaea, Bacteria, and Eukaryota as the fundamental groups.
Asexual reproduction creates identical offspring quickly, whilst sexual reproduction creates variation through combining genetic material from two parents. This variation provides raw material for natural selection to work on.
Key Tip: Evolution isn't about organisms 'trying' to improve - it's about random mutations that happen to be useful in current conditions!
Protein Synthesis and Genetics Applications
Protein synthesis transforms genetic information into working molecules. Ribosomes read the genetic code and assemble amino acids into proteins. Coding DNA contains instructions, whilst non-coding DNA controls when genes are switched on or off.
Modern genetics offers powerful medical applications. Embryo screening detects genetic disorders before birth, helping families make informed decisions. Gene therapy could treat conditions like cystic fibrosis by replacing faulty genes with working copies.
Cloning creates genetically identical organisms through different methods. Cuttings are the simplest plant cloning, tissue culture grows plants from small samples, and embryo transplants clone animals by splitting early embryos.
Family trees track how genetic conditions pass through generations, showing inheritance patterns of conditions like polydactyly . Understanding whether conditions are caused by dominant or recessive alleles helps predict risks for future children.
Key Tip: The genetic code is universal - the same DNA triplets code for the same amino acids in bacteria, plants, and humans!
Ecology and Environmental Impact
Ecosystems are complex networks where communities of organisms interact with their environment. Biotic factors (living things) and abiotic factors both affect organism distribution and biodiversity.
Competition for resources limits population sizes - organisms compete for food, water, territory, and mates. Apex predators sit at the top of food chains, controlling populations of species below them through predation pressure.
The carbon cycle moves carbon between living organisms and the environment through photosynthesis, respiration, and decomposition. Decomposers break down dead material, recycling nutrients back into ecosystems.
Human activities significantly impact ecosystems. Deforestation destroys habitats and reduces biodiversity, whilst climate change alters temperature and rainfall patterns. Understanding these impacts helps us make better environmental decisions for the future.
Key Tip: Energy is lost at each level of a food chain, which explains why there are fewer predators than prey animals in any ecosystem!
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Most popular content: Ecosystem
Most popular content in Biology
Most popular content
English - inspector calls quotes and analysis
Quotes from every main character
English Literature10
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.9/5
App Store
4.8/5
Google Play
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.
Stefan S
iOS user
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.
Samantha Klich
Android user
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.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
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.
Stefan S
iOS user
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.
Samantha Klich
Android user
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.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Essential Biology Terms for GCSE Success
Miriam
@mm_16
Your GCSE biology revision just got easier! This comprehensive guide covers all seven key topics from cell biology to ecology, packed with essential definitions and concepts you need to ace your AQA exam.
Cell Biology Fundamentals
Ever wondered how your body works at the tiniest level? Cell biology is where it all starts, and mastering these terms will give you a solid foundation for everything else in biology.
Cells are the basic building blocks of life, and they come in two main types. Eukaryotic cells (found in plants and animals) have a nucleus that controls everything, whilst prokaryotic cells (bacteria) don't have one. Inside these cells, you'll find organelles - specialised structures like mitochondria (where respiration happens) and chloroplasts (where photosynthesis occurs in plants).
Movement is crucial for cells to survive. Diffusion spreads particles from high to low concentration, osmosis moves water through membranes, and active transport uses energy to move substances against the concentration gradient. Think of it like swimming upstream - it takes effort!
Cell division through mitosis creates identical cells for growth and repair, whilst stem cells are the body's repair kit, able to become any specialised cell type. Understanding how these processes work together will help you tackle more complex biology topics with confidence.
Key Tip: Remember that active transport is the only process that requires energy - it's going against the natural flow!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Organisation and Disease
Your body is brilliantly organised, working like a well-oiled machine from cells to tissues to organs to organ systems. It's this organisation that keeps you alive and healthy every single day.
Your heart pumps blood through different vessels: arteries carry blood away from the heart at high pressure, veins bring it back at low pressure, and tiny capillaries allow exchange of materials. The aorta and pulmonary artery are your major highways, moving oxygenated and deoxygenated blood where they need to go.
Enzymes are your body's speed-up tools - biological catalysts that make reactions happen faster. Amylase breaks down carbohydrates, protease tackles proteins, and lipase handles fats. The lock and key hypothesis explains how enzymes work - substrates must fit perfectly into the enzyme's active site.
Disease comes in two forms: communicable diseases spread between people, whilst non-communicable diseases like cancer don't. Malignant tumours are the dangerous ones that spread, whilst benign tumours stay put. Understanding these differences helps you make sense of how different treatments work.
Key Tip: Think of enzymes like keys - each one only fits specific locks (substrates), and temperature changes can bend the key!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Plant Transport and Heart Health
Plants have their own transport systems that work differently from animals but are just as important. Xylem carries water and minerals up from roots to leaves, whilst phloem moves sugars around the plant through translocation.
Palisade mesophyll tissue is where most photosynthesis happens in leaves - it's packed with chloroplasts to catch maximum light. Spongy mesophyll handles gas exchange, allowing carbon dioxide in and oxygen out. Transpiration is like plant sweating - water evaporates from leaves, creating a pull that draws more water up through the plant.
Heart disease is a major health concern you should understand. Coronary heart disease occurs when fatty deposits block arteries supplying the heart muscle. Doctors can treat this by inserting stents to keep arteries open or prescribing statins to lower cholesterol levels.
Understanding risk factors helps you make informed choices about your health. Some you can't change (like genetics), but others like diet, exercise, and smoking are completely within your control.
Key Tip: Plants don't have hearts, but transpiration creates a powerful suction that can pull water up the tallest trees!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Infection and Response
Your body faces constant attack from pathogens - microorganisms that cause infectious disease - but your immune system is ready for battle. Understanding how infections work and how we fight them is crucial for your health and your exams.
Communicable diseases spread between people and include serious conditions like measles (viral), salmonella (bacterial), and malaria (protist). Each pathogen type requires different treatments - antibiotics kill bacteria but are useless against viruses.
Vaccination is one of medicine's greatest victories, introducing dead or inactive pathogens to train your white blood cells to recognise and fight real infections. Your body's non-specific defences like skin and stomach acid provide the first line of protection.
Clinical drug testing ensures medicines are safe and effective through rigorous stages. Preclinical testing uses cells and animals, followed by double blind trials where neither patients nor researchers know who gets the real drug versus a placebo. This prevents bias and ensures reliable results.
Key Tip: Remember that antibiotics only work on bacteria - taking them for viral infections like colds is pointless and can lead to resistance!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Bioenergetics and Homeostasis
Energy drives everything in biology, and understanding bioenergetics explains how organisms power their lives. Cellular respiration releases energy from glucose - aerobic respiration uses oxygen whilst anaerobic respiration doesn't.
Photosynthesis captures light energy to make glucose, and several factors can limit its rate. Limiting factors include light intensity, carbon dioxide concentration, and temperature. The inverse square law explains how light intensity decreases with distance - double the distance, quarter the intensity.
Homeostasis keeps your internal environment stable despite external changes. It's like your body's thermostat, constantly monitoring and adjusting conditions. Coordination centres like your brain process information from receptors and send signals to effectors that make changes.
Key hormones control different processes: insulin and glucagon regulate blood sugar, adrenaline prepares you for emergencies, and ADH controls water balance in your kidneys. Negative feedback cycles reverse changes to maintain balance - when blood sugar rises, insulin brings it down.
Key Tip: Think of homeostasis like driving a car - you constantly make small adjustments to stay on course rather than dramatic steering changes!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Reproduction and Plant Responses
Your body's reproductive system is controlled by carefully balanced hormones that work in cycles. FSH triggers egg maturation, LH causes egg release, and oestrogen prepares the uterus lining. Understanding these interactions explains both natural fertility and contraception methods.
Modern medicine offers solutions for fertility problems through IVF (in vitro fertilisation), where eggs and sperm meet outside the body before embryo transfer. Embryo screening can detect genetic conditions before implantation.
Plants respond to their environment through growth movements called tropisms. Phototropism makes shoots grow towards light, whilst geotropism (or gravitropism) makes roots grow down and shoots grow up. Plant hormones like auxins, gibberellins, and ethene control these responses.
Your sensory systems detect environmental changes. Reflex actions provide rapid, automatic responses to danger - like pulling your hand from a hot surface before you consciously feel pain. The central nervous system coordinates these responses through the brain and spinal cord.
Key Tip: Plant hormones work differently from animal hormones - they're made in one place but can affect growth throughout the entire plant!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Inheritance and DNA
Your DNA contains the blueprint for life, wound into a double helix structure carrying genetic information in genes. These genes come in different versions called alleles - some dominant (always expressed) and others recessive (only expressed when you have two copies).
Chromosomes package your DNA, and humans have 23 pairs. Sex chromosomes determine gender - XY for males, XX for females. During reproduction, meiosis creates gametes with half the usual chromosome number, restored during fertilisation.
Understanding inheritance patterns helps predict offspring characteristics. Homozygous individuals have identical alleles (like AA or aa), whilst heterozygous individuals have different alleles (like Aa). Punnett squares help calculate the probability of different outcomes.
Modern genetics involves genetic engineering - inserting useful genes from one organism into another. GM crops resist pests or herbicides, whilst gene therapy treats genetic disorders. Selective breeding has been used for thousands of years to develop crops and livestock with desirable traits.
Key Tip: Remember that genotype is what genes you have, but phenotype is what you actually look like - environment can influence how genes are expressed!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Evolution and Classification
Evolution explains how species change over time through natural selection - Charles Darwin's revolutionary idea that organisms with advantageous traits survive and reproduce more successfully. Mutations create genetic variants, and environmental pressures determine which survive.
Fossils provide evidence for evolution, showing how organisms changed over millions of years. Sometimes species become extinct when they can't adapt fast enough to changing conditions. New species form through speciation when populations become isolated and evolve differently.
Scientists classify organisms using the binomial system - each species gets two names (genus and species). The traditional Linnaean system groups organisms into kingdom, phylum, class, order, family, genus, and species. The modern three-domain system recognises Archaea, Bacteria, and Eukaryota as the fundamental groups.
Asexual reproduction creates identical offspring quickly, whilst sexual reproduction creates variation through combining genetic material from two parents. This variation provides raw material for natural selection to work on.
Key Tip: Evolution isn't about organisms 'trying' to improve - it's about random mutations that happen to be useful in current conditions!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Protein Synthesis and Genetics Applications
Protein synthesis transforms genetic information into working molecules. Ribosomes read the genetic code and assemble amino acids into proteins. Coding DNA contains instructions, whilst non-coding DNA controls when genes are switched on or off.
Modern genetics offers powerful medical applications. Embryo screening detects genetic disorders before birth, helping families make informed decisions. Gene therapy could treat conditions like cystic fibrosis by replacing faulty genes with working copies.
Cloning creates genetically identical organisms through different methods. Cuttings are the simplest plant cloning, tissue culture grows plants from small samples, and embryo transplants clone animals by splitting early embryos.
Family trees track how genetic conditions pass through generations, showing inheritance patterns of conditions like polydactyly . Understanding whether conditions are caused by dominant or recessive alleles helps predict risks for future children.
Key Tip: The genetic code is universal - the same DNA triplets code for the same amino acids in bacteria, plants, and humans!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Ecology and Environmental Impact
Ecosystems are complex networks where communities of organisms interact with their environment. Biotic factors (living things) and abiotic factors both affect organism distribution and biodiversity.
Competition for resources limits population sizes - organisms compete for food, water, territory, and mates. Apex predators sit at the top of food chains, controlling populations of species below them through predation pressure.
The carbon cycle moves carbon between living organisms and the environment through photosynthesis, respiration, and decomposition. Decomposers break down dead material, recycling nutrients back into ecosystems.
Human activities significantly impact ecosystems. Deforestation destroys habitats and reduces biodiversity, whilst climate change alters temperature and rainfall patterns. Understanding these impacts helps us make better environmental decisions for the future.
Key Tip: Energy is lost at each level of a food chain, which explains why there are fewer predators than prey animals in any ecosystem!
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
2
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Mock Exam
Quiz
Flashcards
Essay
Similar content
Ecosystem Dynamics Overview
Explore the intricate relationships within ecosystems, focusing on abiotic and biotic factors, climate change impacts, and human influences. This summary covers key concepts such as biodiversity, competition, and environmental changes affecting organisms, particularly salmon in the River Tay. Ideal for National 5 Biology students preparing for exams.
BiologyS4
Photosynthesis Essentials
Explore the critical components and processes of photosynthesis, including chloroplast structure, light-dependent and light-independent reactions, and the role of chlorophyll. This summary provides a clear understanding of how plants convert light energy into glucose, essential for life on Earth.
Biology12
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.
Biology9
Ecology and Biodiversity Insights
Explore key concepts in ecology, including biodiversity, ecosystem dynamics, and human impact on habitats. This summary covers essential topics such as competition, nutrient cycles, and conservation strategies, providing a comprehensive overview for AQA Biology students. Ideal for exam preparation and understanding ecological relationships.
Biology10
Trophic Levels & Ecosystem Dynamics
Explore the intricate relationships within ecosystems through this detailed overview of trophic levels, energy transfer, and biodiversity. This summary highlights key concepts such as food chains, competition, and the impact of human activities on food security and environmental changes. Ideal for students studying ecology and environmental science.
Biology10
Understanding Ecosystems
Explore the fundamentals of ecosystems, including the interactions between biotic (living) and abiotic (non-living) components. This summary covers key concepts such as ecosystem dynamics, nutrient cycles, and energy flows, providing a clear overview for Year 8 students studying biology.
Biology8
Most popular content: Ecosystem
Most popular content in Biology
Most popular content
English - inspector calls quotes and analysis
Quotes from every main character
English Literature10
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.9/5
App Store
4.8/5
Google Play
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.
Stefan S
iOS user
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.
Samantha Klich
Android user
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.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
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.
Stefan S
iOS user
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.
Samantha Klich
Android user
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.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user