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
10 Dec 2025
146
2 pages
isla ๐ซถ @isla
Your body is constantly working behind the scenes to keep everything perfectly balanced, just like a thermostat maintains... Show more
Think of your body as the ultimate control system that never takes a break. Homeostasis is how your body automatically regulates its internal conditions to keep everything running smoothly. It's like having an invisible personal assistant making sure everything stays just right.
Your body maintains several crucial things at optimal levels. Blood glucose concentration stays steady so your cells have energy, while your body temperature stays at exactly 37ยฐC. This temperature control is vital because it keeps your enzymes working properly - if you get too hot or cold, these important proteins stop doing their jobs effectively.
Water levels and ion balance are also carefully controlled. You're constantly losing water through sweating and breathing, but your body cleverly adjusts to maintain the perfect balance.
Remember Homeostasis isn't something you consciously control - it happens automatically to keep you healthy!
Your body uses a brilliant four-step system to maintain balance, and understanding this will help you ace your biology exams. Every response follows the same reliable pattern.
First, there's a stimulus - any change in your environment, like getting too hot or your blood sugar dropping. Receptors then detect these changes, acting like biological sensors that are part of your nervous or hormonal systems.
Coordination centres are the clever control rooms that receive information from receptors and decide what to do about it. Finally, effectors (your muscles or glands) actually carry out the response to fix the problem.
This whole process works through negative feedback - when something changes, your body responds by reversing that change back to normal levels. It's like your body's built-in correction system that keeps everything perfectly balanced.
Top Tip Remember the sequence - Stimulus โ Receptor โ Coordination Centre โ Effector - this pattern appears in every homeostasis example!
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 structure and function of the human excretory system, including the kidneys, urinary system, and the role of ADH in osmoregulation. This summary covers key concepts such as nephron structure, ultrafiltration, selective reabsorption, and the composition of urine. Ideal for Edexcel IGCSE Biology students preparing for exams.
BiologyExplore the essential roles of kidneys in filtering blood, regulating water and ion levels, and the process of deamination. This summary covers nephron structure, filtration, selective reabsorption, and the role of ADH in maintaining homeostasis. Ideal for GCSE biology students.
BiologyExplore the anatomy and physiology of the kidney, focusing on the nephron's role in urine production and osmoregulation. This summary covers key concepts such as the renal cortex, medulla, and the function of ADH in regulating water balance. Ideal for biology students studying the excretory system.
BiologyExplore the mechanisms of kidney function, focusing on the Loop of Henle, osmoregulation, and the role of ADH in maintaining water balance. This summary covers key concepts such as hypertonic urine, aquaporins, and negative feedback in homeostasis, essential for AQA A level biology.
BiologyExplore the roles of the kidneys in urine production, water balance, and the hormonal regulation of blood glucose levels. This summary covers key concepts such as osmoregulation, negative feedback mechanisms, and the impact of diabetes on homeostasis. Ideal for AQA Biology students preparing for Paper 2.
BiologyExplore the essential roles of the kidneys in the excretory system, including the processes of ultrafiltration, reabsorption, and waste release. This summary covers key concepts such as nephron structure, osmoregulation, and the formation of urine, providing a clear understanding of kidney function for students.
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
isla ๐ซถ
@isla
Your body is constantly working behind the scenes to keep everything perfectly balanced, just like a thermostat maintains room temperature. This amazing process is called homeostasis, and it's what keeps you alive and healthy every single day.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Think of your body as the ultimate control system that never takes a break. Homeostasis is how your body automatically regulates its internal conditions to keep everything running smoothly. It's like having an invisible personal assistant making sure everything stays just right.
Your body maintains several crucial things at optimal levels. Blood glucose concentration stays steady so your cells have energy, while your body temperature stays at exactly 37ยฐC. This temperature control is vital because it keeps your enzymes working properly - if you get too hot or cold, these important proteins stop doing their jobs effectively.
Water levels and ion balance are also carefully controlled. You're constantly losing water through sweating and breathing, but your body cleverly adjusts to maintain the perfect balance.
Remember: Homeostasis isn't something you consciously control - it happens automatically to keep you healthy!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Your body uses a brilliant four-step system to maintain balance, and understanding this will help you ace your biology exams. Every response follows the same reliable pattern.
First, there's a stimulus - any change in your environment, like getting too hot or your blood sugar dropping. Receptors then detect these changes, acting like biological sensors that are part of your nervous or hormonal systems.
Coordination centres are the clever control rooms that receive information from receptors and decide what to do about it. Finally, effectors (your muscles or glands) actually carry out the response to fix the problem.
This whole process works through negative feedback - when something changes, your body responds by reversing that change back to normal levels. It's like your body's built-in correction system that keeps everything perfectly balanced.
Top Tip: Remember the sequence - Stimulus โ Receptor โ Coordination Centre โ Effector - this pattern appears in every homeostasis example!
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 structure and function of the human excretory system, including the kidneys, urinary system, and the role of ADH in osmoregulation. This summary covers key concepts such as nephron structure, ultrafiltration, selective reabsorption, and the composition of urine. Ideal for Edexcel IGCSE Biology students preparing for exams.
BiologyExplore the essential roles of kidneys in filtering blood, regulating water and ion levels, and the process of deamination. This summary covers nephron structure, filtration, selective reabsorption, and the role of ADH in maintaining homeostasis. Ideal for GCSE biology students.
BiologyExplore the anatomy and physiology of the kidney, focusing on the nephron's role in urine production and osmoregulation. This summary covers key concepts such as the renal cortex, medulla, and the function of ADH in regulating water balance. Ideal for biology students studying the excretory system.
BiologyExplore the mechanisms of kidney function, focusing on the Loop of Henle, osmoregulation, and the role of ADH in maintaining water balance. This summary covers key concepts such as hypertonic urine, aquaporins, and negative feedback in homeostasis, essential for AQA A level biology.
BiologyExplore the roles of the kidneys in urine production, water balance, and the hormonal regulation of blood glucose levels. This summary covers key concepts such as osmoregulation, negative feedback mechanisms, and the impact of diabetes on homeostasis. Ideal for AQA Biology students preparing for Paper 2.
BiologyExplore the essential roles of the kidneys in the excretory system, including the processes of ultrafiltration, reabsorption, and waste release. This summary covers key concepts such as nephron structure, osmoregulation, and the formation of urine, providing a clear understanding of kidney function for students.
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