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14 Dec 2025
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AQA Biology Paper 1 Revision Guide - Higher Level
Armani Johnson
@armaniohnson
1 / 10
Food Tests You Need to Know
Ever wondered how scientists identify what's actually in your food? These simple chemical tests will show you exactly what nutrients are present.
For starch, you'll use iodine solution which turns a distinctive blue-black colour when starch is detected. Benedict's solution tests for sugars - heat your sample in a water bath and watch for colour changes from blue to yellow, green, or brick red depending on sugar concentration.
Protein testing uses Biuret solution, which creates a purple or lilac colour when proteins are present. For lipids (fats), add ethanol to your ground food sample - a milky or cloudy appearance means fats are there. Remember to keep ethanol away from naked flames since it's highly flammable, and always wear safety specs when handling corrosive chemicals.
Quick Tip: The colour changes are your key to success - memorise blue-black for starch, brick red for high sugar, and purple for protein!
Microscope Basics
Microscopes might look complicated, but once you know the main parts, they're actually quite straightforward to use.
The eyepiece lens is where you look through, whilst objective lenses of different magnifications give you varying levels of detail. Your sample sits on the stage, and the light source illuminates everything from below.
The two focus knobs are crucial - use the coarse focus knob for major adjustments and the fine focus knob for sharp, detailed images. Getting comfortable with these controls will make all your practical work much easier.
Remember: Always start with the lowest magnification objective lens first!
Using a Microscope Step-by-Step
Following the right sequence when using a microscope will give you clear, detailed images every time.
Start by placing a thin sample on your slide, then position it on the stage and switch on the lamp. Begin with the smallest objective lens - this gives you a wider field of view to locate your specimen easily.
Use the coarse focus knob first to get a rough image, then fine-tune with the fine focus knob. Once you've got a clear view, you can switch to higher magnification objective lenses for more detail, but remember to refocus each time you change lenses.
Pro Tip: Moving the stage down prevents you from accidentally crushing your slide when focusing!
Heart Structure and Blood Vessels
Your heart is basically a muscular pump with four chambers that keeps blood flowing around your entire body.
The right atrium and right ventricle handle blood going to your lungs, whilst the left atrium and left ventricle pump blood around the rest of your body. The major blood vessels include the aorta (carrying oxygenated blood from the heart), vena cava (returning deoxygenated blood), and pulmonary arteries and veins connecting to your lungs.
Understanding this layout helps explain how blood circulation works as a continuous loop through your body and lungs.
Key Point: The heart has four chambers - two atria (top) and two ventricles (bottom).
How Your Heart Actually Works
Your heart functions as a double pump because each side has a different job - the right side sends blood to your lungs whilst the left side pumps it everywhere else.
The left ventricle has much thicker muscle than the right because it needs more power to push blood all around your body, not just to your nearby lungs. This makes perfect sense when you think about the distances involved.
Your heart's rhythm comes from special pacemaker cells located in the right atrium. These cells create electrical signals that coordinate your heartbeat without any conscious effort from you.
Cool Fact: Your heart beats around 100,000 times per day without you even thinking about it!
Respiratory System and Gas Exchange
Your lungs are perfectly designed for swapping oxygen and carbon dioxide between your blood and the air you breathe.
Air travels through your trachea, then splits into bronchi and smaller bronchioles before reaching tiny air sacs called alveoli. This is where the magic happens - oxygen diffuses from your lungs into your blood whilst carbon dioxide moves the opposite direction.
Alveoli speed up diffusion through three key features: their massive surface area, walls that are only one cell thick, and an excellent blood supply. These adaptations make gas exchange incredibly efficient.
Remember: Diffusion always moves from high concentration to low concentration!
Exam Success Tips
Smart exam technique can seriously boost your biology grades, so these strategies are worth memorising.
Carcinogens are chemicals that cause cancer - a key term you'll definitely encounter. For your papers, aim for around 383 marks to hit grade 7, or 321 marks for grade 6 out of the total 570 marks available.
Never write 'it' in your answers - always name the specific thing you're discussing. Include actual values from any tables or graphs in your responses, and remember that lines of best fit can be curves, not just straight lines. For longer 4-6 mark questions, use bullet points to structure your answers clearly.
Exam Hack: Being specific with scientific terms and data values shows examiners you really understand the content!
Hygiene and Disease Prevention
Good hygiene practices are your first line of defence against harmful pathogens, and they're surprisingly effective at keeping you healthy.
Hygienic measures work by either destroying pathogens completely or washing them away before they can spread to other people. Simple actions like using antibacterial products to clean surfaces, washing your hands regularly, and sneezing into a handkerchief all help prevent infection.
These basic habits might seem obvious, but they're actually incredibly powerful tools for stopping diseases from spreading through communities.
Daily Habit: Proper hand washing for 20 seconds removes most harmful bacteria and viruses!
Your Immune System Response
When pathogens get past your basic defences like skin and stomach acid, your immune system kicks into action with some serious biological weaponry.
Your immune system consists of various types of white blood cells, each designed for specific functions in fighting infection. These cells work together as a coordinated defence network to identify and eliminate threats to your body.
Once activated, your immune system not only fights the current infection but often creates lasting protection against the same pathogen in future encounters.
Amazing Fact: Your immune system can remember thousands of different pathogens and respond faster if they return!
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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
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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
AQA Biology Paper 1 Revision Guide - Higher Level
Armani Johnson
@armaniohnson
These biology notes cover essential lab techniques, body systems, and disease prevention that you'll need for your GCSE exams. From food testing and microscopy to understanding how your heart and lungs work, these concepts form the backbone of practical biology.
Food Tests You Need to Know
Ever wondered how scientists identify what's actually in your food? These simple chemical tests will show you exactly what nutrients are present.
For starch, you'll use iodine solution which turns a distinctive blue-black colour when starch is detected. Benedict's solution tests for sugars - heat your sample in a water bath and watch for colour changes from blue to yellow, green, or brick red depending on sugar concentration.
Protein testing uses Biuret solution, which creates a purple or lilac colour when proteins are present. For lipids (fats), add ethanol to your ground food sample - a milky or cloudy appearance means fats are there. Remember to keep ethanol away from naked flames since it's highly flammable, and always wear safety specs when handling corrosive chemicals.
Quick Tip: The colour changes are your key to success - memorise blue-black for starch, brick red for high sugar, and purple for protein!
Sign up to see the contentIt's free!
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Improve your grades
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By signing up you accept Terms of Service and Privacy Policy
Microscope Basics
Microscopes might look complicated, but once you know the main parts, they're actually quite straightforward to use.
The eyepiece lens is where you look through, whilst objective lenses of different magnifications give you varying levels of detail. Your sample sits on the stage, and the light source illuminates everything from below.
The two focus knobs are crucial - use the coarse focus knob for major adjustments and the fine focus knob for sharp, detailed images. Getting comfortable with these controls will make all your practical work much easier.
Remember: Always start with the lowest magnification objective lens first!
Sign up to see the contentIt's free!
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Improve your grades
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Using a Microscope Step-by-Step
Following the right sequence when using a microscope will give you clear, detailed images every time.
Start by placing a thin sample on your slide, then position it on the stage and switch on the lamp. Begin with the smallest objective lens - this gives you a wider field of view to locate your specimen easily.
Use the coarse focus knob first to get a rough image, then fine-tune with the fine focus knob. Once you've got a clear view, you can switch to higher magnification objective lenses for more detail, but remember to refocus each time you change lenses.
Pro Tip: Moving the stage down prevents you from accidentally crushing your slide when focusing!
Sign up to see the contentIt's free!
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Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Heart Structure and Blood Vessels
Your heart is basically a muscular pump with four chambers that keeps blood flowing around your entire body.
The right atrium and right ventricle handle blood going to your lungs, whilst the left atrium and left ventricle pump blood around the rest of your body. The major blood vessels include the aorta (carrying oxygenated blood from the heart), vena cava (returning deoxygenated blood), and pulmonary arteries and veins connecting to your lungs.
Understanding this layout helps explain how blood circulation works as a continuous loop through your body and lungs.
Key Point: The heart has four chambers - two atria (top) and two ventricles (bottom).
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Improve your grades
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How Your Heart Actually Works
Your heart functions as a double pump because each side has a different job - the right side sends blood to your lungs whilst the left side pumps it everywhere else.
The left ventricle has much thicker muscle than the right because it needs more power to push blood all around your body, not just to your nearby lungs. This makes perfect sense when you think about the distances involved.
Your heart's rhythm comes from special pacemaker cells located in the right atrium. These cells create electrical signals that coordinate your heartbeat without any conscious effort from you.
Cool Fact: Your heart beats around 100,000 times per day without you even thinking about it!
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Improve your grades
Join milions of students
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Respiratory System and Gas Exchange
Your lungs are perfectly designed for swapping oxygen and carbon dioxide between your blood and the air you breathe.
Air travels through your trachea, then splits into bronchi and smaller bronchioles before reaching tiny air sacs called alveoli. This is where the magic happens - oxygen diffuses from your lungs into your blood whilst carbon dioxide moves the opposite direction.
Alveoli speed up diffusion through three key features: their massive surface area, walls that are only one cell thick, and an excellent blood supply. These adaptations make gas exchange incredibly efficient.
Remember: Diffusion always moves from high concentration to low concentration!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Exam Success Tips
Smart exam technique can seriously boost your biology grades, so these strategies are worth memorising.
Carcinogens are chemicals that cause cancer - a key term you'll definitely encounter. For your papers, aim for around 383 marks to hit grade 7, or 321 marks for grade 6 out of the total 570 marks available.
Never write 'it' in your answers - always name the specific thing you're discussing. Include actual values from any tables or graphs in your responses, and remember that lines of best fit can be curves, not just straight lines. For longer 4-6 mark questions, use bullet points to structure your answers clearly.
Exam Hack: Being specific with scientific terms and data values shows examiners you really understand the content!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Hygiene and Disease Prevention
Good hygiene practices are your first line of defence against harmful pathogens, and they're surprisingly effective at keeping you healthy.
Hygienic measures work by either destroying pathogens completely or washing them away before they can spread to other people. Simple actions like using antibacterial products to clean surfaces, washing your hands regularly, and sneezing into a handkerchief all help prevent infection.
These basic habits might seem obvious, but they're actually incredibly powerful tools for stopping diseases from spreading through communities.
Daily Habit: Proper hand washing for 20 seconds removes most harmful bacteria and viruses!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Your Immune System Response
When pathogens get past your basic defences like skin and stomach acid, your immune system kicks into action with some serious biological weaponry.
Your immune system consists of various types of white blood cells, each designed for specific functions in fighting infection. These cells work together as a coordinated defence network to identify and eliminate threats to your body.
Once activated, your immune system not only fights the current infection but often creates lasting protection against the same pathogen in future encounters.
Amazing Fact: Your immune system can remember thousands of different pathogens and respond faster if they return!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
We thought you’d never ask...
What is the Knowunity AI companion?
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.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
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Students love us — and so will you.
4.9/5
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4.8/5
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