Subjects
Maths
Chemistry
Biology
English Language
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Responding to change (a2 only)
Infection and response
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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
96
4 pages
lucy garvie @lucygarvie_idbg
Your nervous system is basically your body's electrical wiring - it's constantly sending messages between your brain and... Show more
Think of your nervous system as having three main jobs that happen lightning-fast every second. First, it gathers information through sensation - detecting everything from the temperature of your morning coffee to the sound of your alarm. Then comes integration, where your brain processes this info and decides what to do about it. Finally, there's the response - your muscles contract or glands release hormones to react appropriately.
The system splits into two main parts the central nervous system (CNS), which includes your brain and spinal cord, and the peripheral nervous system (PNS), made up of all the nerves that carry messages to and from the CNS. Your PNS further divides into the somatic nervous system (controls voluntary movements like waving) and the autonomic nervous system (handles involuntary stuff like digestion).
The whole process works through a simple chain receptors detect changes in your environment, send electrical impulses through the CNS, which then triggers effectors like muscles or glands to produce a response. It's like a perfectly coordinated relay race happening inside you constantly.
Quick Tip Remember the flow as STIMULI → RECEPTOR → CNS → EFFECTORS → RESPONSE - this sequence appears in almost every nervous system exam question!
Your autonomic nervous system runs on autopilot, controlling everything you don't consciously think about. It's split into two opposing teams that work like a biological seesaw - the sympathetic and parasympathetic systems.
The sympathetic system is your "fight or flight" response - it kicks in when you're stressed, excited, or need quick action. It cranks up your heart rate, speeds up breathing, but slows down digestion because your body's prioritising survival over lunch. Think of it as your internal energy drink.
Meanwhile, the parasympathetic system is all about "rest and digest" mode. When you're chilled out, this system takes charge - slowing your heart rate, easing your breathing, and boosting digestion so you can properly process that food. It's like your body's way of hitting the reset button.
These systems rarely work at the same time - when one's active, the other takes a back seat. This balance keeps your body responding appropriately to different situations without you having to consciously control every single process.
Remember Sympathetic = Stress response (speeds things up), Parasympathetic = Peace response (slows things down and aids digestion).
Neural pathways are like the different routes your nerve impulses can take, and there are three main types you need to know. Each one serves a specific purpose in how your nervous system processes information.
Converging pathways bring multiple nerve signals together into one neuron - imagine several streams flowing into one river. This happens in your retina where multiple rod cells converge, making your eyes more sensitive to dim light through a process called summation.
Diverging pathways work the opposite way - one signal splits off to reach multiple destinations simultaneously. When you pick up a pencil, one nerve impulse diverges to control several hand muscles at once, allowing your fingers to work as a coordinated team rather than individual units.
Reverberating pathways create loops where later neurons connect back to earlier ones, allowing the same signal to circulate repeatedly. This clever design keeps essential rhythmic activities like breathing going automatically - the pathway keeps stimulating itself without needing constant new input from your brain.
Study Hack Think "Converge = Combine, Diverge = Divide, Reverberate = Repeat" to remember the three pathway types quickly during exams.
Your brain is essentially mission control for your entire body, packed with billions of interconnected neurons working together. Despite weighing only about 1.4kg, it's responsible for everything from your personality to keeping you breathing whilst you sleep.
The brain has four key regions, each with specialist jobs. The cerebrum (with its outer cerebral cortex) handles the sophisticated stuff - your intelligence, personality, conscious thoughts, and complex abilities like language and memory. It's heavily folded to pack maximum surface area into your skull.
The cerebellum might be smaller, but it's crucial for balance, coordination, and smooth muscular activity - think of it as your body's internal gyroscope. Meanwhile, the medulla oblongata controls unconscious activities that keep you alive, like breathing and heart rate.
What makes the brain incredible is how these regions work together seamlessly. You can consciously decide to speak (cerebrum), while your cerebellum coordinates the precise muscle movements needed, and your medulla keeps you breathing throughout the entire conversation.
Exam Focus Learn the four brain regions and their functions - this commonly appears as a labelling question or short-answer section on biology papers.
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 classification of living organisms into five kingdoms: Prokaryotae, Protoctista, Fungi, Plantae, and Animalia. This summary covers Carl Woese's classification system, the differences between prokaryotic and eukaryotic cells, and key characteristics of each kingdom. Ideal for students studying biological classification and levels of organization.
BiologyComprehensive summary of AQA A-Level Biology Year 1, covering key topics such as cellular structure, protein synthesis, immune response, gas exchange, and more. Ideal for exam preparation and understanding biological concepts. Includes detailed insights into cellular processes, biological classification, and the circulatory system.
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
lucy garvie
@lucygarvie_idbg
Your nervous system is basically your body's electrical wiring - it's constantly sending messages between your brain and every part of your body. Whether you're consciously deciding to pick up your phone or unconsciously breathing whilst you sleep, different parts... Show more
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Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Think of your nervous system as having three main jobs that happen lightning-fast every second. First, it gathers information through sensation - detecting everything from the temperature of your morning coffee to the sound of your alarm. Then comes integration, where your brain processes this info and decides what to do about it. Finally, there's the response - your muscles contract or glands release hormones to react appropriately.
The system splits into two main parts: the central nervous system (CNS), which includes your brain and spinal cord, and the peripheral nervous system (PNS), made up of all the nerves that carry messages to and from the CNS. Your PNS further divides into the somatic nervous system (controls voluntary movements like waving) and the autonomic nervous system (handles involuntary stuff like digestion).
The whole process works through a simple chain: receptors detect changes in your environment, send electrical impulses through the CNS, which then triggers effectors like muscles or glands to produce a response. It's like a perfectly coordinated relay race happening inside you constantly.
Quick Tip: Remember the flow as STIMULI → RECEPTOR → CNS → EFFECTORS → RESPONSE - this sequence appears in almost every nervous system exam question!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Your autonomic nervous system runs on autopilot, controlling everything you don't consciously think about. It's split into two opposing teams that work like a biological seesaw - the sympathetic and parasympathetic systems.
The sympathetic system is your "fight or flight" response - it kicks in when you're stressed, excited, or need quick action. It cranks up your heart rate, speeds up breathing, but slows down digestion because your body's prioritising survival over lunch. Think of it as your internal energy drink.
Meanwhile, the parasympathetic system is all about "rest and digest" mode. When you're chilled out, this system takes charge - slowing your heart rate, easing your breathing, and boosting digestion so you can properly process that food. It's like your body's way of hitting the reset button.
These systems rarely work at the same time - when one's active, the other takes a back seat. This balance keeps your body responding appropriately to different situations without you having to consciously control every single process.
Remember: Sympathetic = Stress response (speeds things up), Parasympathetic = Peace response (slows things down and aids digestion).
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Neural pathways are like the different routes your nerve impulses can take, and there are three main types you need to know. Each one serves a specific purpose in how your nervous system processes information.
Converging pathways bring multiple nerve signals together into one neuron - imagine several streams flowing into one river. This happens in your retina where multiple rod cells converge, making your eyes more sensitive to dim light through a process called summation.
Diverging pathways work the opposite way - one signal splits off to reach multiple destinations simultaneously. When you pick up a pencil, one nerve impulse diverges to control several hand muscles at once, allowing your fingers to work as a coordinated team rather than individual units.
Reverberating pathways create loops where later neurons connect back to earlier ones, allowing the same signal to circulate repeatedly. This clever design keeps essential rhythmic activities like breathing going automatically - the pathway keeps stimulating itself without needing constant new input from your brain.
Study Hack: Think "Converge = Combine, Diverge = Divide, Reverberate = Repeat" to remember the three pathway types quickly during exams.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Your brain is essentially mission control for your entire body, packed with billions of interconnected neurons working together. Despite weighing only about 1.4kg, it's responsible for everything from your personality to keeping you breathing whilst you sleep.
The brain has four key regions, each with specialist jobs. The cerebrum (with its outer cerebral cortex) handles the sophisticated stuff - your intelligence, personality, conscious thoughts, and complex abilities like language and memory. It's heavily folded to pack maximum surface area into your skull.
The cerebellum might be smaller, but it's crucial for balance, coordination, and smooth muscular activity - think of it as your body's internal gyroscope. Meanwhile, the medulla oblongata controls unconscious activities that keep you alive, like breathing and heart rate.
What makes the brain incredible is how these regions work together seamlessly. You can consciously decide to speak (cerebrum), while your cerebellum coordinates the precise muscle movements needed, and your medulla keeps you breathing throughout the entire conversation.
Exam Focus: Learn the four brain regions and their functions - this commonly appears as a labelling question or short-answer section on biology papers.
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 classification of living organisms into five kingdoms: Prokaryotae, Protoctista, Fungi, Plantae, and Animalia. This summary covers Carl Woese's classification system, the differences between prokaryotic and eukaryotic cells, and key characteristics of each kingdom. Ideal for students studying biological classification and levels of organization.
BiologyComprehensive summary of AQA A-Level Biology Year 1, covering key topics such as cellular structure, protein synthesis, immune response, gas exchange, and more. Ideal for exam preparation and understanding biological concepts. Includes detailed insights into cellular processes, biological classification, and the circulatory system.
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