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
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Biology
6 Dec 2025
176
2 pages
Andrew Caicedo Ortiz @andrewcaicedo
Cell biology is all about understanding the building blocks of life - cells and how they work. From... Show more
Mitosis is how your body grows and repairs itself by creating identical copies of cells. During the cell cycle, DNA replicates, chromosomes double, then split to opposite ends before the cell divides into two identical daughter cells. It's like cellular photocopying!
Stem cells are the ultimate shape-shifters. Embryonic stem cells can become almost any type of cell, making them incredibly valuable for treating diseases like diabetes and paralysis. Adult stem cells are more limited but still useful for replacing blood cells and other tissues.
Transport across membranes happens in three main ways. Diffusion moves particles from crowded to less crowded areas (like perfume spreading across a room). Osmosis is specifically water moving through membranes. Active transport uses energy to move substances uphill against the natural flow.
Microscopes let us see the invisible world of cells. Light microscopes are great for basic viewing (up to 1500x magnification), but electron microscopes can zoom in up to 500,000 times with incredible detail. Remember magnification = image size ÷ real object size.
Exam Tip Surface area, temperature, and concentration gradients all affect how fast diffusion happens - the bigger the difference, the faster the movement!
Ever wondered what makes you "you" at the most basic level? It all starts with cells! Eukaryotic cells (like yours) have a nucleus that acts like the cell's control centre, containing all the genetic information. Prokaryotic cells (bacteria) keep their DNA floating freely in loops instead.
The key difference between plant and animal cells is that plants have extra bits like chloroplasts for photosynthesis and a permanent vacuole for storage. Both types have mitochondria (the powerhouses), ribosomes (protein factories), and cell membranes that control what gets in and out.
Specialised cells are like cellular superheroes - each one has a specific job. Sperm cells are built for swimming with their tails and energy-packed mitochondria, whilst nerve cells are incredibly long to send messages across your body quickly.
Quick Tip Remember that structure always matches function - if a cell needs to do a specific job, its shape and parts will be perfectly designed for that task!
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.
4
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the processes of cell differentiation, the cell cycle, mitosis, and meiosis. Understand the roles of stem cells, their potency, and the significance of specialized cells like erythrocytes and neutrophils. This summary also addresses ethical concerns surrounding stem cell use and highlights the organization of cells into tissues and organs.
BiologyExplore the detailed stages of mitosis, including Prophase, Metaphase, Anaphase, and Telophase. This summary highlights key events such as chromatin condensation, spindle apparatus formation, and cytokinesis, essential for A Level Biology students. Understand the cell cycle phases and their significance in cell division.
BiologyExplore key concepts in cell biology, including microscopy techniques, cell structures, and the differences between eukaryotic and prokaryotic cells. This summary covers essential information for GCSE Biology Paper One, focusing on specialized cells and their functions. Ideal for quick revision and understanding of cellular structures and functions.
BiologyExplore essential concepts for Biology Paper 1, including eukaryotic and prokaryotic cell structures, mitosis, enzyme functions, and the human circulatory and digestive systems. This comprehensive summary is perfect for exam preparation and understanding key biological processes.
BiologyExplore the essential processes of photosynthesis, including the role of chlorophyll, light-dependent reactions, and factors affecting plant growth. This summary covers the conversion of carbon dioxide and water into glucose, the importance of light, and adaptations of leaves for optimal photosynthesis. Ideal for GCSE Biology students seeking to understand plant productivity and the significance of photosynthesis in ecosystems.
BiologyExplore the stages of mitosis in detail, including interphase, prophase, metaphase, anaphase, and telophase. This concise summary highlights the key processes involved in cell division, essential for GCSE Edexcel and AQA students. Understand how mitosis contributes to growth and cell replacement, and use the PMAT acronym to remember the sequence of events.
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
Andrew Caicedo Ortiz
@andrewcaicedo
Cell biology is all about understanding the building blocks of life - cells and how they work. From the tiniest bacteria to complex human tissues, everything living is made up of cells that have amazing abilities to grow, divide, and... Show more
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Mitosis is how your body grows and repairs itself by creating identical copies of cells. During the cell cycle, DNA replicates, chromosomes double, then split to opposite ends before the cell divides into two identical daughter cells. It's like cellular photocopying!
Stem cells are the ultimate shape-shifters. Embryonic stem cells can become almost any type of cell, making them incredibly valuable for treating diseases like diabetes and paralysis. Adult stem cells are more limited but still useful for replacing blood cells and other tissues.
Transport across membranes happens in three main ways. Diffusion moves particles from crowded to less crowded areas (like perfume spreading across a room). Osmosis is specifically water moving through membranes. Active transport uses energy to move substances uphill against the natural flow.
Microscopes let us see the invisible world of cells. Light microscopes are great for basic viewing (up to 1500x magnification), but electron microscopes can zoom in up to 500,000 times with incredible detail. Remember: magnification = image size ÷ real object size.
Exam Tip: Surface area, temperature, and concentration gradients all affect how fast diffusion happens - the bigger the difference, the faster the movement!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Ever wondered what makes you "you" at the most basic level? It all starts with cells! Eukaryotic cells (like yours) have a nucleus that acts like the cell's control centre, containing all the genetic information. Prokaryotic cells (bacteria) keep their DNA floating freely in loops instead.
The key difference between plant and animal cells is that plants have extra bits like chloroplasts for photosynthesis and a permanent vacuole for storage. Both types have mitochondria (the powerhouses), ribosomes (protein factories), and cell membranes that control what gets in and out.
Specialised cells are like cellular superheroes - each one has a specific job. Sperm cells are built for swimming with their tails and energy-packed mitochondria, whilst nerve cells are incredibly long to send messages across your body quickly.
Quick Tip: Remember that structure always matches function - if a cell needs to do a specific job, its shape and parts will be perfectly designed for that task!
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.
4
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the processes of cell differentiation, the cell cycle, mitosis, and meiosis. Understand the roles of stem cells, their potency, and the significance of specialized cells like erythrocytes and neutrophils. This summary also addresses ethical concerns surrounding stem cell use and highlights the organization of cells into tissues and organs.
BiologyExplore the detailed stages of mitosis, including Prophase, Metaphase, Anaphase, and Telophase. This summary highlights key events such as chromatin condensation, spindle apparatus formation, and cytokinesis, essential for A Level Biology students. Understand the cell cycle phases and their significance in cell division.
BiologyExplore key concepts in cell biology, including microscopy techniques, cell structures, and the differences between eukaryotic and prokaryotic cells. This summary covers essential information for GCSE Biology Paper One, focusing on specialized cells and their functions. Ideal for quick revision and understanding of cellular structures and functions.
BiologyExplore essential concepts for Biology Paper 1, including eukaryotic and prokaryotic cell structures, mitosis, enzyme functions, and the human circulatory and digestive systems. This comprehensive summary is perfect for exam preparation and understanding key biological processes.
BiologyExplore the essential processes of photosynthesis, including the role of chlorophyll, light-dependent reactions, and factors affecting plant growth. This summary covers the conversion of carbon dioxide and water into glucose, the importance of light, and adaptations of leaves for optimal photosynthesis. Ideal for GCSE Biology students seeking to understand plant productivity and the significance of photosynthesis in ecosystems.
BiologyExplore the stages of mitosis in detail, including interphase, prophase, metaphase, anaphase, and telophase. This concise summary highlights the key processes involved in cell division, essential for GCSE Edexcel and AQA students. Understand how mitosis contributes to growth and cell replacement, and use the PMAT acronym to remember the sequence of events.
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