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
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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
1 Dec 2025
23
5 pages
Your body is basically a massive city made up of trillions of tiny building blocks called cells! These... Show more
Think of cells as the LEGO bricks of life - they're the smallest units that make up every living thing on Earth. You've got trillions of these little powerhouses working 24/7 inside your body right now!
Each cell contains your genetic information (basically your body's instruction manual), but different types have completely different jobs. It's like having a massive workforce where everyone has their own specialty.
Quick Fact You're literally made of trillions of cells working together - that's more cells than there are stars in our galaxy!
The main types you need to know about include red blood cells, white blood cells, T-cells, stem cells, plus prokaryotic and eukaryotic cells. Each one has its own superpower that keeps you healthy and alive.
Red blood cells (also called erythrocytes) are absolute legends - they're the most common cells in your entire body! Their main job is being your personal oxygen delivery service and carbon dioxide removal team.
These disc-shaped cells pick up oxygen from your lungs and taxi it around to every part of your body that needs it. Then they collect the waste carbon dioxide and bring it back to your lungs so you can breathe it out.
Your bone marrow (the spongy stuff inside your bones) is like a red blood cell factory, constantly making fresh ones. Each red blood cell works hard for about 120 days (roughly 4 months) before it gets tired and dies.
Remember This Without red blood cells, your body would be like a city with no delivery trucks - nothing would get where it needs to go!
White blood cells (leukocytes) are basically your body's security team. They patrol your bloodstream looking for troublemakers like bacteria, viruses, and other nasty invaders that could make you sick.
When you get a cut or infection, these cellular heroes rush to the scene to fight off germs and help your body heal. They're why that scraped knee eventually stops being red and painful!
T-cells are special types of white blood cells that are particularly good at hunting down specific threats. Like white blood cells, they're made in your bone marrow and are part of your immune system's elite forces.
Cool Connection Ever wondered why you don't get the same cold twice? Your T-cells remember previous invaders and can fight them off faster next time!
Prokaryotic cells are like the basic model of cellular life - they're single-celled organisms that don't have a nucleus (control centre). Think of bacteria - they're simple but incredibly effective at surviving.
These cells have their DNA floating freely inside, which lets them carry out biochemical reactions in their cytoplasm . Simple but brilliant!
Eukaryotic cells are the advanced version - they're multicellular and have a proper nucleus to store their DNA safely. These cells can reproduce themselves through mitosis (cell division).
Easy Memory Trick Pro = basic/simple, Eu = fancy/complex. Prokaryotic cells are the basic models, eukaryotic cells are the luxury versions!
The main job of eukaryotic cells is self-preservation (staying alive) and self-reproduction (making copies of themselves).
Stem cells are absolutely mind-blowing - they're like the ultimate shape-shifters of the cellular world! These special cells can transform into literally any other type of cell your body needs.
Scientists are fascinated by stem cells because they could potentially help treat serious diseases like cancer and heart disease. The research is still ongoing, but the possibilities are incredible.
Stem cell research has even shown it might be possible to grow organs or tissues in labs. While human cloning remains controversial and largely theoretical, the medical applications could revolutionise how we treat illnesses.
Future Focus Understanding stem cells now could help you appreciate the amazing medical breakthroughs that might happen in your lifetime!
These cellular superstars represent hope for millions of people with currently incurable conditions.
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 โ all at your fingertips.
2
Smart Tools NEW
Transform this note into: โ 50+ Practice Questions โ Interactive Flashcards โ Full Mock Exam โ Essay Outlines
Explore the fundamental differences between prokaryotic and eukaryotic cells, including their structure, size, genetic material, and methods of division. This summary provides a clear comparison of bacterial cells and those of animals, plants, and fungi, highlighting key characteristics essential for understanding cell biology.
BiologyExplore the fundamental concepts of cell biology, including eukaryotic and prokaryotic cells, specialized cell functions, and key processes like osmosis and mitosis. This summary provides a comprehensive overview for Paper 1 revision, focusing on cell structure, differentiation, and transport mechanisms. Ideal for students preparing for biology exams.
BiologyExplore the key differences and similarities between prokaryotic and eukaryotic cells, including their structures, organelles, and functions. This summary highlights essential concepts such as cell membranes, nuclei, and organelle presence, making it a valuable resource for understanding cellular biology.
BiologyExplore the essential components and functions of prokaryotic and eukaryotic cells, including plant and bacterial cell structures. This summary covers chloroplasts, mitochondria, ribosomes, and more, providing a clear understanding of cellular processes. Ideal for AQA Combined Science Foundation Level students.
BiologyEukaryotes and prokaryotes
BiologyExplore the fundamental concepts of cellular biology, focusing on the differences between eukaryotic and prokaryotic cells. This summary covers key structures such as the nucleus, cytoplasm, mitochondria, ribosomes, and chloroplasts, along with their functions in animal and plant cells. Ideal for students preparing for biology exams.
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 itโs 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 didnโt even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโm 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 ๐๐๐ฒ๐ค๐โจ๐๐ฎ
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 itโs 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 didnโt even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโm 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 ๐๐๐ฒ๐ค๐โจ๐๐ฎ
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
Your body is basically a massive city made up of trillions of tiny building blocks called cells! These microscopic units are what keep you alive and functioning every single day, from carrying oxygen around your body to fighting off that... Show more
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Think of cells as the LEGO bricks of life - they're the smallest units that make up every living thing on Earth. You've got trillions of these little powerhouses working 24/7 inside your body right now!
Each cell contains your genetic information (basically your body's instruction manual), but different types have completely different jobs. It's like having a massive workforce where everyone has their own specialty.
Quick Fact: You're literally made of trillions of cells working together - that's more cells than there are stars in our galaxy!
The main types you need to know about include red blood cells, white blood cells, T-cells, stem cells, plus prokaryotic and eukaryotic cells. Each one has its own superpower that keeps you healthy and alive.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Red blood cells (also called erythrocytes) are absolute legends - they're the most common cells in your entire body! Their main job is being your personal oxygen delivery service and carbon dioxide removal team.
These disc-shaped cells pick up oxygen from your lungs and taxi it around to every part of your body that needs it. Then they collect the waste carbon dioxide and bring it back to your lungs so you can breathe it out.
Your bone marrow (the spongy stuff inside your bones) is like a red blood cell factory, constantly making fresh ones. Each red blood cell works hard for about 120 days (roughly 4 months) before it gets tired and dies.
Remember This: Without red blood cells, your body would be like a city with no delivery trucks - nothing would get where it needs to go!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
White blood cells (leukocytes) are basically your body's security team. They patrol your bloodstream looking for troublemakers like bacteria, viruses, and other nasty invaders that could make you sick.
When you get a cut or infection, these cellular heroes rush to the scene to fight off germs and help your body heal. They're why that scraped knee eventually stops being red and painful!
T-cells are special types of white blood cells that are particularly good at hunting down specific threats. Like white blood cells, they're made in your bone marrow and are part of your immune system's elite forces.
Cool Connection: Ever wondered why you don't get the same cold twice? Your T-cells remember previous invaders and can fight them off faster next time!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Prokaryotic cells are like the basic model of cellular life - they're single-celled organisms that don't have a nucleus (control centre). Think of bacteria - they're simple but incredibly effective at surviving.
These cells have their DNA floating freely inside, which lets them carry out biochemical reactions in their cytoplasm . Simple but brilliant!
Eukaryotic cells are the advanced version - they're multicellular and have a proper nucleus to store their DNA safely. These cells can reproduce themselves through mitosis (cell division).
Easy Memory Trick: Pro = basic/simple, Eu = fancy/complex. Prokaryotic cells are the basic models, eukaryotic cells are the luxury versions!
The main job of eukaryotic cells is self-preservation (staying alive) and self-reproduction (making copies of themselves).
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 absolutely mind-blowing - they're like the ultimate shape-shifters of the cellular world! These special cells can transform into literally any other type of cell your body needs.
Scientists are fascinated by stem cells because they could potentially help treat serious diseases like cancer and heart disease. The research is still ongoing, but the possibilities are incredible.
Stem cell research has even shown it might be possible to grow organs or tissues in labs. While human cloning remains controversial and largely theoretical, the medical applications could revolutionise how we treat illnesses.
Future Focus: Understanding stem cells now could help you appreciate the amazing medical breakthroughs that might happen in your lifetime!
These cellular superstars represent hope for millions of people with currently incurable conditions.
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 โ all at your fingertips.
2
Smart Tools NEW
Transform this note into: โ 50+ Practice Questions โ Interactive Flashcards โ Full Mock Exam โ Essay Outlines
Explore the fundamental differences between prokaryotic and eukaryotic cells, including their structure, size, genetic material, and methods of division. This summary provides a clear comparison of bacterial cells and those of animals, plants, and fungi, highlighting key characteristics essential for understanding cell biology.
BiologyExplore the fundamental concepts of cell biology, including eukaryotic and prokaryotic cells, specialized cell functions, and key processes like osmosis and mitosis. This summary provides a comprehensive overview for Paper 1 revision, focusing on cell structure, differentiation, and transport mechanisms. Ideal for students preparing for biology exams.
BiologyExplore the key differences and similarities between prokaryotic and eukaryotic cells, including their structures, organelles, and functions. This summary highlights essential concepts such as cell membranes, nuclei, and organelle presence, making it a valuable resource for understanding cellular biology.
BiologyExplore the essential components and functions of prokaryotic and eukaryotic cells, including plant and bacterial cell structures. This summary covers chloroplasts, mitochondria, ribosomes, and more, providing a clear understanding of cellular processes. Ideal for AQA Combined Science Foundation Level students.
BiologyEukaryotes and prokaryotes
BiologyExplore the fundamental concepts of cellular biology, focusing on the differences between eukaryotic and prokaryotic cells. This summary covers key structures such as the nucleus, cytoplasm, mitochondria, ribosomes, and chloroplasts, along with their functions in animal and plant cells. Ideal for students preparing for biology exams.
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 itโs 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 didnโt even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโm 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 ๐๐๐ฒ๐ค๐โจ๐๐ฎ
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 itโs 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 didnโt even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโm 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 ๐๐๐ฒ๐ค๐โจ๐๐ฎ
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