Subjects
Maths
Chemistry
Biology
English Language
History
Responding to change (a2 only)
Infection and response
Homeostasis and response
Energy transfers (a2 only)
Cell biology
Organisms respond to changes in their internal and external environments (a-level only)
Biological molecules
Organisation
Substance exchange
Bioenergetics
Genetic information & variation
Inheritance, variation and evolution
Genetics & ecosystems (a2 only)
Ecology
Cells
Show all topics
Britain & the wider world: 1745 -1901
1l the quest for political stability: germany, 1871-1991
The cold war
Inter-war germany
Medieval period: 1066 -1509
2d religious conflict and the church in england, c1529-c1570
2o democracy and nazism: germany, 1918-1945
1f industrialisation and the people: britain, c1783-1885
1c the tudors: england, 1485-1603
2m wars and welfare: britain in transition, 1906-1957
World war two & the holocaust
2n revolution and dictatorship: russia, 1917-1953
2s the making of modern britain, 1951-2007
World war one
Britain: 1509 -1745
Show all topics
Biology
6 Dec 2025
955
5 pages
mehek @thisismetryingg
Biology covers loads of fascinating topics that help explain how living things work, from the tiniest cells to... Show more
Every living thing is made of cells, which are like tiny factories with different parts doing specific jobs. Plant cells and animal cells share some organelles but have key differences that you need to know for exams.
Both cell types contain a nucleus (the control centre with genetic material), cytoplasm (where most chemical reactions happen), mitochondria (powerhouses for respiration), and ribosomes (protein factories). The cell membrane acts like a bouncer, controlling what enters and leaves.
Plant cells have three extra features a tough cell wall made of cellulose for support, chloroplasts for photosynthesis, and a large vacuole filled with cell sap. Bacterial cells are different altogether - they're prokaryotic (no proper nucleus) whilst plant and animal cells are eukaryotic (with a nucleus).
Quick Tip Remember that substances move around cells through diffusion (high to low concentration), osmosis (water through membranes), and active transport (low to high concentration, needs energy).
Understanding cardiovascular disease and cancer helps explain major health risks you'll encounter in exams. Cardiovascular disease happens when fatty deposits clog coronary arteries, potentially causing heart attacks - risk factors include smoking, high blood pressure, and poor diet.
Cancer occurs when cells divide uncontrollably, forming benign tumours (harmless lumps) or dangerous malignant tumours (aggressive and spreading). Key risk factors include smoking, poor diet, sun exposure, and unprotected sex.
Leaf structure is perfectly designed for photosynthesis and gas exchange. The upper epidermis protects the leaf, whilst palisade mesophyll contains loads of chloroplasts for photosynthesis. Spongy mesophyll has air spaces for gas exchange, and guard cells control the stomata (tiny pores).
Transpiration (water loss from leaves) increases with bright light, high temperature, and wind, but decreases with high humidity. The xylem transports water whilst phloem carries food around the plant.
Disease Alert Know your pathogens - viruses (measles, HIV), bacteria (salmonella, gonorrhoea), fungi (rose black spot), and parasites (malaria) all spread differently and cause different symptoms.
Your immune system is like your body's personal army, with white blood cells leading the charge against pathogens. These clever cells produce antibodies to recognise invaders, antitoxins to neutralise poisons, and can directly consume harmful microorganisms.
Vaccination works by introducing small amounts of dead or inactive pathogens, allowing your immune system to develop antibodies safely. This means future infections can be dealt with quickly - it's why diseases like smallpox have been completely wiped out.
New drug development involves testing for toxicity (how much is safe), efficacy (how well it works), and finding the right dose. Many medicines come from natural sources - penicillin from mould, digitalis from foxgloves for heart problems, and aspirin from willow bark.
There are pros and cons to vaccination programmes - they save lives and create herd immunity, but can cause side effects and don't always work for everyone.
Historical Fact Alexander Fleming discovered penicillin in 1928, revolutionising medicine and saving millions of lives from bacterial infections.
Stem cells are incredibly versatile cells that could treat diseases like diabetes and cancer, but their use raises ethical questions about destroying embryos. The debate continues between potential medical breakthroughs and moral concerns.
Photosynthesis is the process plants use to make food water + carbon dioxide + light → glucose + oxygen. This endothermic reaction (takes in energy) happens in chloroplasts and needs sunlight. Meanwhile, respiration releases energy from glucose - it's the opposite process and happens in all living cells.
Digestive enzymes break down your food using the 'lock and key' model. Amylase tackles starch, protease breaks down proteins, and lipase handles fats. These enzymes are produced in your salivary glands, stomach, pancreas, and small intestine.
Anaerobic respiration happens without oxygen - in yeast, it produces alcohol (useful for drinks and bread), whilst in your muscles during exercise, it creates lactic acid that makes you feel the burn.
Energy Tip Aerobic respiration produces much more energy than anaerobic respiration, which is why you can't sprint forever without oxygen!
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.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
10
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the essential components of cell structure and function, including the nucleus, cell membrane, cytoplasm, mitochondria, vacuoles, cell walls, chloroplasts, chromosomes, plasmids, and ribosomes. This summary provides insights into their roles in various cell types, including animal, plant, bacterial, and fungal cells. Ideal for N5 Biology students preparing for exams.
BiologyExplore the key structures of animal cells, including the nucleus, mitochondria, and ribosomes, along with their essential functions in cellular processes. This summary highlights the differences between animal and plant cells, focusing on the role of each component in respiration and protein synthesis.
BiologyExplore the essential components and functions of animal, plant, and bacterial cells. This summary covers key structures such as the nucleus, mitochondria, chloroplasts, and more, providing a clear understanding of cellular biology for GCSE students. Ideal for exam preparation and quick revision.
BiologyExplore the fundamental concepts of cell structure, including animal and plant cells, eukaryotic and prokaryotic cells, and the specialization of cells in both plants and animals. This summary covers key topics such as microscopy techniques, the transport systems in plants (xylem and phloem), and the unique adaptations of specialized cells. Ideal for AQA GCSE Biology students.
BiologyExplore the intricacies of animal and plant cell structures, including the nucleus, mitochondria, and chloroplasts. Understand the functions of specialized cells, the roles of xylem and phloem in plant transport, and the differences between prokaryotic and eukaryotic cells. This summary is essential for mastering cellular biology concepts.
BiologyExplore the key differences and similarities between plant and animal cells. This summary includes labeled diagrams, definitions of essential components such as the nucleus, cell membrane, and cell wall, along with detailed descriptions of cell structures and their functions. Ideal for biology revision.
BiologyApp Store
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
mehek
@thisismetryingg
Biology covers loads of fascinating topics that help explain how living things work, from the tiniest cells to entire organ systems. You'll explore everything from plant and animal cells to diseases, photosynthesis, and how your body digests food and fights... Show more
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Every living thing is made of cells, which are like tiny factories with different parts doing specific jobs. Plant cells and animal cells share some organelles but have key differences that you need to know for exams.
Both cell types contain a nucleus (the control centre with genetic material), cytoplasm (where most chemical reactions happen), mitochondria (powerhouses for respiration), and ribosomes (protein factories). The cell membrane acts like a bouncer, controlling what enters and leaves.
Plant cells have three extra features: a tough cell wall made of cellulose for support, chloroplasts for photosynthesis, and a large vacuole filled with cell sap. Bacterial cells are different altogether - they're prokaryotic (no proper nucleus) whilst plant and animal cells are eukaryotic (with a nucleus).
Quick Tip: Remember that substances move around cells through diffusion (high to low concentration), osmosis (water through membranes), and active transport (low to high concentration, needs energy).
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Understanding cardiovascular disease and cancer helps explain major health risks you'll encounter in exams. Cardiovascular disease happens when fatty deposits clog coronary arteries, potentially causing heart attacks - risk factors include smoking, high blood pressure, and poor diet.
Cancer occurs when cells divide uncontrollably, forming benign tumours (harmless lumps) or dangerous malignant tumours (aggressive and spreading). Key risk factors include smoking, poor diet, sun exposure, and unprotected sex.
Leaf structure is perfectly designed for photosynthesis and gas exchange. The upper epidermis protects the leaf, whilst palisade mesophyll contains loads of chloroplasts for photosynthesis. Spongy mesophyll has air spaces for gas exchange, and guard cells control the stomata (tiny pores).
Transpiration (water loss from leaves) increases with bright light, high temperature, and wind, but decreases with high humidity. The xylem transports water whilst phloem carries food around the plant.
Disease Alert: Know your pathogens - viruses (measles, HIV), bacteria (salmonella, gonorrhoea), fungi (rose black spot), and parasites (malaria) all spread differently and cause different symptoms.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Your immune system is like your body's personal army, with white blood cells leading the charge against pathogens. These clever cells produce antibodies to recognise invaders, antitoxins to neutralise poisons, and can directly consume harmful microorganisms.
Vaccination works by introducing small amounts of dead or inactive pathogens, allowing your immune system to develop antibodies safely. This means future infections can be dealt with quickly - it's why diseases like smallpox have been completely wiped out.
New drug development involves testing for toxicity (how much is safe), efficacy (how well it works), and finding the right dose. Many medicines come from natural sources - penicillin from mould, digitalis from foxgloves for heart problems, and aspirin from willow bark.
There are pros and cons to vaccination programmes - they save lives and create herd immunity, but can cause side effects and don't always work for everyone.
Historical Fact: Alexander Fleming discovered penicillin in 1928, revolutionising medicine and saving millions of lives from bacterial infections.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Stem cells are incredibly versatile cells that could treat diseases like diabetes and cancer, but their use raises ethical questions about destroying embryos. The debate continues between potential medical breakthroughs and moral concerns.
Photosynthesis is the process plants use to make food: water + carbon dioxide + light → glucose + oxygen. This endothermic reaction (takes in energy) happens in chloroplasts and needs sunlight. Meanwhile, respiration releases energy from glucose - it's the opposite process and happens in all living cells.
Digestive enzymes break down your food using the 'lock and key' model. Amylase tackles starch, protease breaks down proteins, and lipase handles fats. These enzymes are produced in your salivary glands, stomach, pancreas, and small intestine.
Anaerobic respiration happens without oxygen - in yeast, it produces alcohol (useful for drinks and bread), whilst in your muscles during exercise, it creates lactic acid that makes you feel the burn.
Energy Tip: Aerobic respiration produces much more energy than anaerobic respiration, which is why you can't sprint forever without oxygen!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
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.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
10
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the essential components of cell structure and function, including the nucleus, cell membrane, cytoplasm, mitochondria, vacuoles, cell walls, chloroplasts, chromosomes, plasmids, and ribosomes. This summary provides insights into their roles in various cell types, including animal, plant, bacterial, and fungal cells. Ideal for N5 Biology students preparing for exams.
BiologyExplore the key structures of animal cells, including the nucleus, mitochondria, and ribosomes, along with their essential functions in cellular processes. This summary highlights the differences between animal and plant cells, focusing on the role of each component in respiration and protein synthesis.
BiologyExplore the essential components and functions of animal, plant, and bacterial cells. This summary covers key structures such as the nucleus, mitochondria, chloroplasts, and more, providing a clear understanding of cellular biology for GCSE students. Ideal for exam preparation and quick revision.
BiologyExplore the fundamental concepts of cell structure, including animal and plant cells, eukaryotic and prokaryotic cells, and the specialization of cells in both plants and animals. This summary covers key topics such as microscopy techniques, the transport systems in plants (xylem and phloem), and the unique adaptations of specialized cells. Ideal for AQA GCSE Biology students.
BiologyExplore the intricacies of animal and plant cell structures, including the nucleus, mitochondria, and chloroplasts. Understand the functions of specialized cells, the roles of xylem and phloem in plant transport, and the differences between prokaryotic and eukaryotic cells. This summary is essential for mastering cellular biology concepts.
BiologyExplore the key differences and similarities between plant and animal cells. This summary includes labeled diagrams, definitions of essential components such as the nucleus, cell membrane, and cell wall, along with detailed descriptions of cell structures and their functions. Ideal for biology revision.
BiologyApp Store
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
Sociology