Subjects
Maths
Chemistry
Biology
English Language
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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
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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
9 Dec 2025
1,035
2 pages
Diffusion and osmosis in cell transport are crucial processes in biology, particularly for AQA Combined Sciencestudents. This... Show more
This page delves into specific examples of adaptations for efficient substance exchange in different biological structures.
Villi are adapted for efficient nutrient absorption with
Highlight These adaptations of villi for absorption significantly increase the efficiency of nutrient uptake in the small intestine.
Alveoli are specialized for gas exchange with
Example The thin, moist walls of alveoli allow for efficient oxygen and carbon dioxide exchange between the air and bloodstream.
Fish gills are adapted for aquatic gas exchange
Vocabulary Filaments are thin, thread-like structures that increase the surface area of gills.
The page concludes with information about a required practical skill
Highlight Students must be able to accurately measure length, mass, and volume to study osmosis in cells, using various tissue examples.
These examples illustrate how different organisms and structures are adapted for efficient substance exchange, a key concept in GCSE Biology and AQA Combined Science.
This page provides a comprehensive overview of the three main types of cell transport diffusion, osmosis, and active transport. Each process is defined and explained in terms of particle movement and energy requirements.
Definition Diffusion is the spreading out of particles resulting in a net movement from an area of higher concentration to an area of lower concentration.
Example Oxygen diffuses from the air into the alveoli in the lungs.
Highlight Diffusion and osmosis are passive processes that do not require energy, while active transport needs energy from respiration.
The page also discusses factors affecting the rate of diffusion
Vocabulary Concentration gradient refers to the difference in concentration between two areas.
The text explains adaptations for exchanging substances, comparing single-celled and multi-cellular organisms
Example Single-celled organisms have a large surface area to volume ratio, allowing efficient molecule transport across cell membranes.
Multi-cellular organisms, with their smaller surface area to volume ratio, require specialized organ systems for effective substance exchange.
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.
29
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore essential strategies for tackling extended response questions in National 5 Biology. This resource covers key concepts such as cellular transport, fermentation processes, and human body systems, providing insights into effective answering techniques. Ideal for students preparing for exams, this summary includes past paper questions and marking schemes to enhance understanding and performance.
BiologyExplore key concepts in cell biology, including specialized exchange surfaces, diffusion, osmosis, and active transport. This summary covers essential adaptations for efficient substance exchange in multicellular organisms, cell division, and the structure of eukaryotic and prokaryotic cells. Ideal for AQA Combined Science (Higher Tier) revision.
BiologyExplore key concepts in cell biology, including microscopy techniques, bacterial growth, mitosis, stem cells, and transport mechanisms like diffusion and osmosis. This summary covers essential practicals and theoretical knowledge for AQA Biology, perfect for exam preparation.
BiologyExplore the essential processes of diffusion, osmosis, and active transport in cells. This summary covers key concepts such as concentration gradients, the role of temperature and surface area in diffusion, and the mechanisms of cellular transport, including the function of transport proteins and the significance of cellular respiration. Ideal for students studying plant transport systems and cellular processes.
BiologyExplore comprehensive insights into 6-mark QER questions for the WJEC Biology GCSE. This resource covers key topics such as substance exchange, the carbon and nitrogen cycles, respiration, and the circulatory system, providing essential knowledge for exam preparation.
BiologyExplore key concepts in homeostasis, including hormonal coordination, the nervous system, and the impact of abiotic and biotic factors on ecosystems. This comprehensive study note covers essential topics such as glucose regulation, the menstrual cycle, and the importance of biodiversity. Ideal for GCSE Biology revision, this resource provides a clear overview of cellular processes, energy transfer, and the dynamics of ecosystems. Type: Summary.
BiologyQuotes from every main character
English LiteratureApp 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
Diffusion and osmosis in cell transport are crucial processes in biology, particularly for AQA Combined Sciencestudents. This summary covers the key concepts of diffusion, osmosis, and active transport, their definitions, energy requirements, and examples. It also explores factors affecting... Show more
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
This page delves into specific examples of adaptations for efficient substance exchange in different biological structures.
Villi are adapted for efficient nutrient absorption with:
Highlight: These adaptations of villi for absorption significantly increase the efficiency of nutrient uptake in the small intestine.
Alveoli are specialized for gas exchange with:
Example: The thin, moist walls of alveoli allow for efficient oxygen and carbon dioxide exchange between the air and bloodstream.
Fish gills are adapted for aquatic gas exchange:
Vocabulary: Filaments are thin, thread-like structures that increase the surface area of gills.
The page concludes with information about a required practical skill:
Highlight: Students must be able to accurately measure length, mass, and volume to study osmosis in cells, using various tissue examples.
These examples illustrate how different organisms and structures are adapted for efficient substance exchange, a key concept in GCSE Biology and AQA Combined Science.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
This page provides a comprehensive overview of the three main types of cell transport: diffusion, osmosis, and active transport. Each process is defined and explained in terms of particle movement and energy requirements.
Definition: Diffusion is the spreading out of particles resulting in a net movement from an area of higher concentration to an area of lower concentration.
Example: Oxygen diffuses from the air into the alveoli in the lungs.
Highlight: Diffusion and osmosis are passive processes that do not require energy, while active transport needs energy from respiration.
The page also discusses factors affecting the rate of diffusion:
Vocabulary: Concentration gradient refers to the difference in concentration between two areas.
The text explains adaptations for exchanging substances, comparing single-celled and multi-cellular organisms:
Example: Single-celled organisms have a large surface area to volume ratio, allowing efficient molecule transport across cell membranes.
Multi-cellular organisms, with their smaller surface area to volume ratio, require specialized organ systems for effective substance exchange.
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.
29
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore essential strategies for tackling extended response questions in National 5 Biology. This resource covers key concepts such as cellular transport, fermentation processes, and human body systems, providing insights into effective answering techniques. Ideal for students preparing for exams, this summary includes past paper questions and marking schemes to enhance understanding and performance.
BiologyExplore key concepts in cell biology, including specialized exchange surfaces, diffusion, osmosis, and active transport. This summary covers essential adaptations for efficient substance exchange in multicellular organisms, cell division, and the structure of eukaryotic and prokaryotic cells. Ideal for AQA Combined Science (Higher Tier) revision.
BiologyExplore key concepts in cell biology, including microscopy techniques, bacterial growth, mitosis, stem cells, and transport mechanisms like diffusion and osmosis. This summary covers essential practicals and theoretical knowledge for AQA Biology, perfect for exam preparation.
BiologyExplore the essential processes of diffusion, osmosis, and active transport in cells. This summary covers key concepts such as concentration gradients, the role of temperature and surface area in diffusion, and the mechanisms of cellular transport, including the function of transport proteins and the significance of cellular respiration. Ideal for students studying plant transport systems and cellular processes.
BiologyExplore comprehensive insights into 6-mark QER questions for the WJEC Biology GCSE. This resource covers key topics such as substance exchange, the carbon and nitrogen cycles, respiration, and the circulatory system, providing essential knowledge for exam preparation.
BiologyExplore key concepts in homeostasis, including hormonal coordination, the nervous system, and the impact of abiotic and biotic factors on ecosystems. This comprehensive study note covers essential topics such as glucose regulation, the menstrual cycle, and the importance of biodiversity. Ideal for GCSE Biology revision, this resource provides a clear overview of cellular processes, energy transfer, and the dynamics of ecosystems. Type: Summary.
BiologyQuotes from every main character
English LiteratureApp 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