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
3 Dec 2025
288
5 pages
Lena @lena_ftpy
Ever wondered how we can see tiny cells and what makes them tick? Microscopes are our window into... Show more
You'll use microscopes loads in biology, so understanding how they work is crucial for your studies. Magnification tells you how many times bigger the image appears compared to the real object, whilst resolving power is about how clearly you can distinguish between two close points.
Light microscopes have been around since the 1600s and use light beams to create images up to x2000 magnification. They're brilliant for studying living specimens and won't break the bank. Electron microscopes are the heavy hitters - developed in the 1930s, they use electron beams and can magnify up to x2000000 with much better detail.
The key measurements you'll need are metres (m), millimetres (mm), micrometres (µm), and nanometres (nm). Remember there are 1000 mm in a metre, 1,000,000 µm in a metre, and 1,000,000,000 nm in a metre.
Quick Tip Total magnification = eyepiece magnification × objective magnification. You'll use this formula in practicals!
Cells are literally the building blocks of everything alive - including you! Think of them as tiny factories where all the important stuff happens. Both animal and plant cells share some key structures that you absolutely need to know.
The nucleus is like the cell's control centre, containing DNA and directing all activities. The cell membrane acts as a selective barrier, controlling what gets in and out. Cytoplasm is the jelly-like substance where chemical reactions happen, whilst mitochondria are the powerhouses releasing energy through respiration.
Plant cells have some exclusive features that make them special. The cell wall (made of cellulose) provides extra support and strength. Chloroplasts contain chlorophyll for photosynthesis - that's how plants make their own food! The large vacuole filled with cell sap helps keep the plant rigid and upright.
Memory Trick Plant cells have a "CPV combo" that animal cells don't - Cell wall, cHloroplasts, and Vacuole!
Here's where cells get properly interesting - they're not all the same! Eukaryotic cells (like animal and plant cells) have their DNA safely tucked away in a nucleus. Prokaryotic cells (like bacteria) have their genetic material floating freely in the cytoplasm without a nucleus.
Bacterial cells are much smaller but incredibly important. They've got some unique features flagella (protein strands that whip about for movement), a cell wall that's not made of cellulose, and a slime capsule for protection. Plasmids are extra DNA loops that can make bacteria resistant to antibiotics.
Orders of magnitude help compare sizes of different objects. If something is about 10 times bigger, it's one order of magnitude larger (10¹). If it's 100 times bigger, that's two orders of magnitude (10²). This becomes really useful when comparing cells of different types.
Real-world Connection Understanding bacterial cells is crucial for medicine - it's how we develop antibiotics and fight infections!
Plants are basically made up of different specialist cells, each perfectly designed for their job. Photosynthetic cells are the food-makers, packed with chloroplasts containing chlorophyll to capture sunlight. Their large vacuoles keep them rigid so leaves can position themselves for maximum sun exposure.
Root hair cells are the plant's absorption specialists. They've got a massive surface area to soak up water and minerals from soil, plus loads of mitochondria to power active transport. It's like having tiny straws with built-in energy generators.
Transport is handled by two key systems. Xylem vessels are like plant plumbing - they're hollow tubes strengthened with lignin to move water and minerals upward. Phloem cells work with companion cells to transport dissolved sugars around the plant through special sieve plates.
Study Tip Remember that structure always matches function - if a cell needs to absorb lots of something, it'll have a large surface area!
Animal cells are the ultimate specialists - each type is perfectly adapted for its specific job. Sperm cells are built for one mission reaching and fertilising an egg. They've got a long tail for swimming, mitochondria for energy, and an acrosome packed with enzymes to break through the egg's membrane.
Nerve cells are your body's electrical network, transmitting impulses across long distances. Their long axons are covered in a myelin sheath (like electrical insulation), whilst multiple dendrites connect with other neurons. It's basically biological wiring that makes your brain and body communicate.
Muscle cells are the movers and shakers, literally! They're loaded with mitochondria for energy and contain special proteins that slide over each other during contraction. They even store glycogen that can be quickly converted to glucose when energy is needed fast.
Exam Focus Questions often ask you to link structure to function - always explain HOW each adaptation helps the cell do its job better!
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.
3
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 key concepts in GCSE Biology, focusing on cell structures, functions, and human body systems. This summary covers essential topics such as plant and animal cells, cellular processes, the circulatory and digestive systems, and the implications of diseases like cancer and cardiovascular issues. Ideal for AQA GCSE students preparing for Paper 1.
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 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
Lena
@lena_ftpy
Ever wondered how we can see tiny cells and what makes them tick? Microscopes are our window into the microscopic world, revealing the building blocks of all living things. From the basic structures that keep cells alive to the specialised... Show more
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
You'll use microscopes loads in biology, so understanding how they work is crucial for your studies. Magnification tells you how many times bigger the image appears compared to the real object, whilst resolving power is about how clearly you can distinguish between two close points.
Light microscopes have been around since the 1600s and use light beams to create images up to x2000 magnification. They're brilliant for studying living specimens and won't break the bank. Electron microscopes are the heavy hitters - developed in the 1930s, they use electron beams and can magnify up to x2000000 with much better detail.
The key measurements you'll need are metres (m), millimetres (mm), micrometres (µm), and nanometres (nm). Remember: there are 1000 mm in a metre, 1,000,000 µm in a metre, and 1,000,000,000 nm in a metre.
Quick Tip: Total magnification = eyepiece magnification × objective magnification. You'll use this formula in practicals!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Cells are literally the building blocks of everything alive - including you! Think of them as tiny factories where all the important stuff happens. Both animal and plant cells share some key structures that you absolutely need to know.
The nucleus is like the cell's control centre, containing DNA and directing all activities. The cell membrane acts as a selective barrier, controlling what gets in and out. Cytoplasm is the jelly-like substance where chemical reactions happen, whilst mitochondria are the powerhouses releasing energy through respiration.
Plant cells have some exclusive features that make them special. The cell wall (made of cellulose) provides extra support and strength. Chloroplasts contain chlorophyll for photosynthesis - that's how plants make their own food! The large vacuole filled with cell sap helps keep the plant rigid and upright.
Memory Trick: Plant cells have a "CPV combo" that animal cells don't - Cell wall, cHloroplasts, and Vacuole!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Here's where cells get properly interesting - they're not all the same! Eukaryotic cells (like animal and plant cells) have their DNA safely tucked away in a nucleus. Prokaryotic cells (like bacteria) have their genetic material floating freely in the cytoplasm without a nucleus.
Bacterial cells are much smaller but incredibly important. They've got some unique features: flagella (protein strands that whip about for movement), a cell wall that's not made of cellulose, and a slime capsule for protection. Plasmids are extra DNA loops that can make bacteria resistant to antibiotics.
Orders of magnitude help compare sizes of different objects. If something is about 10 times bigger, it's one order of magnitude larger (10¹). If it's 100 times bigger, that's two orders of magnitude (10²). This becomes really useful when comparing cells of different types.
Real-world Connection: Understanding bacterial cells is crucial for medicine - it's how we develop antibiotics and fight infections!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Plants are basically made up of different specialist cells, each perfectly designed for their job. Photosynthetic cells are the food-makers, packed with chloroplasts containing chlorophyll to capture sunlight. Their large vacuoles keep them rigid so leaves can position themselves for maximum sun exposure.
Root hair cells are the plant's absorption specialists. They've got a massive surface area to soak up water and minerals from soil, plus loads of mitochondria to power active transport. It's like having tiny straws with built-in energy generators.
Transport is handled by two key systems. Xylem vessels are like plant plumbing - they're hollow tubes strengthened with lignin to move water and minerals upward. Phloem cells work with companion cells to transport dissolved sugars around the plant through special sieve plates.
Study Tip: Remember that structure always matches function - if a cell needs to absorb lots of something, it'll have a large surface area!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Animal cells are the ultimate specialists - each type is perfectly adapted for its specific job. Sperm cells are built for one mission: reaching and fertilising an egg. They've got a long tail for swimming, mitochondria for energy, and an acrosome packed with enzymes to break through the egg's membrane.
Nerve cells are your body's electrical network, transmitting impulses across long distances. Their long axons are covered in a myelin sheath (like electrical insulation), whilst multiple dendrites connect with other neurons. It's basically biological wiring that makes your brain and body communicate.
Muscle cells are the movers and shakers, literally! They're loaded with mitochondria for energy and contain special proteins that slide over each other during contraction. They even store glycogen that can be quickly converted to glucose when energy is needed fast.
Exam Focus: Questions often ask you to link structure to function - always explain HOW each adaptation helps the cell do its job better!
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.
3
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 key concepts in GCSE Biology, focusing on cell structures, functions, and human body systems. This summary covers essential topics such as plant and animal cells, cellular processes, the circulatory and digestive systems, and the implications of diseases like cancer and cardiovascular issues. Ideal for AQA GCSE students preparing for Paper 1.
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 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