These practicals are your essential hands-on experiments for biology GCSE... Show more
Sociology
English LiteratureSign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
527
•
Updated Mar 25, 2026
•
Comprehensive Notes for AQA GCSE Biology Paper 1 Practicals
H
Harry Middleton
@gsce_help
1 / 5
Looking at Cells and Investigating Osmosis
Observing plant cells is dead easy once you get the hang of it. You'll peel off a thin layer of onion skin, pop it on a slide with some water, and add iodine solution to make the cells visible. The trick is using the lowest magnification first to find your cells, then switching to higher powers for detail.
When drawing what you see, use continuous lines with no gaps and always include the magnification. Safety-wise, keep iodine solution away from your skin and eyes - it's not dangerous but it stains everything!
Osmosis experiments use potato cylinders in different sugar concentrations. Cut three identical cylinders, weigh them, then leave overnight in solutions ranging from pure water to concentrated sugar. The potatoes will gain or lose mass depending on water movement.
Top tip: Always remove excess water with a paper towel before weighing - you want the potato's mass, not the solution clinging to it!
Understanding Osmosis Results and Food Tests
The osmosis results make perfect sense when you think about it. Sugar molecules are too chunky to pass through cell membranes, but water molecules slip through easily. In concentrated sugar solutions, water leaves the potato (making it lighter), whilst in pure water, it moves in (making it heavier).
Always remove potato skin because it acts as an extra barrier, and use identical cylinder sizes so the surface area for osmosis stays constant.
Food tests are your chemical detectives for identifying nutrients. Iodine turns blue-black for starch, Benedict's solution changes from blue to brick red for sugars (needs heating in a water bath), Biuret reagent goes purple for proteins, and the ethanol test makes lipids go cloudy.
Remember: Benedict's test is quantitative - different sugar concentrations give different colours from green (low) to brick red (high).
Enzyme Activity and Growing Microorganisms
Testing pH effects on amylase shows how enzymes work best at specific conditions. You'll mix starch, amylase, and different pH buffers, then test drops with iodine every 30 seconds. When the iodine stops turning blue-black, all the starch has been broken down.
The optimum pH might fall between your test values, so don't be surprised if your results aren't perfectly clear-cut. Timing every 30 seconds gives approximate results, and colour changes can be gradual.
Growing microorganisms requires aseptic technique to prevent contamination. Sterilise everything with flame, tape petri dishes so they can't fall open, and incubate upside down at 25°C to stop harmful bacteria thriving.
Safety first: 25°C prevents dangerous pathogens from growing, whilst higher temperatures in schools could create health risks.
Antibiotics and Photosynthesis Experiments
Testing antibiotic effectiveness uses the same sterile techniques but adds filter paper discs soaked in different antibiotics. The zone of inhibition (clear area where bacteria can't grow) shows which antibiotic works best. Calculate the area using πr² to compare effectiveness properly.
Photosynthesis experiments measure oxygen bubble production from pondweed at different light distances. Use LED lights to avoid heat affecting your results, and sodium hydrogen carbonate solution to provide plenty of CO₂.
Count bubbles produced in one minute, but be aware this method has limitations - bubbles come too fast and aren't uniform sizes. Better results come from measuring oxygen volume with a gas syringe.
Key insight: When you double the distance from the light, bubble production drops by four times - this demonstrates the inverse square law of light intensity.
Understanding Light Intensity and Distance
The relationship between distance and light intensity follows a predictable pattern that's crucial for your exams. As distance increases, light intensity decreases dramatically - specifically following the inverse square law.
This means if you move your pondweed twice as far from the light source, it receives four times less light energy. Consequently, photosynthesis rate drops by the same factor, producing far fewer oxygen bubbles.
Understanding this relationship helps explain why plants grow differently at various distances from light sources, and why measuring precise distances matters in your experiments.
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.
Most popular content: Diffusion and Osmosis
Most popular content in Biology
Most popular content
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.6/5
App Store
4.7/5
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 Knowunity AI. 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 Knowunity AI. 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
Comprehensive Notes for AQA GCSE Biology Paper 1 Practicals
H
Harry Middleton
@gsce_help
These practicals are your essential hands-on experiments for biology GCSE - the ones that actually come up in your exams! From peering at onion cells under a microscope to testing what makes bacteria grow, these six experiments give you the... Show more
Looking at Cells and Investigating Osmosis
Observing plant cells is dead easy once you get the hang of it. You'll peel off a thin layer of onion skin, pop it on a slide with some water, and add iodine solution to make the cells visible. The trick is using the lowest magnification first to find your cells, then switching to higher powers for detail.
When drawing what you see, use continuous lines with no gaps and always include the magnification. Safety-wise, keep iodine solution away from your skin and eyes - it's not dangerous but it stains everything!
Osmosis experiments use potato cylinders in different sugar concentrations. Cut three identical cylinders, weigh them, then leave overnight in solutions ranging from pure water to concentrated sugar. The potatoes will gain or lose mass depending on water movement.
Top tip: Always remove excess water with a paper towel before weighing - you want the potato's mass, not the solution clinging to it!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Understanding Osmosis Results and Food Tests
The osmosis results make perfect sense when you think about it. Sugar molecules are too chunky to pass through cell membranes, but water molecules slip through easily. In concentrated sugar solutions, water leaves the potato (making it lighter), whilst in pure water, it moves in (making it heavier).
Always remove potato skin because it acts as an extra barrier, and use identical cylinder sizes so the surface area for osmosis stays constant.
Food tests are your chemical detectives for identifying nutrients. Iodine turns blue-black for starch, Benedict's solution changes from blue to brick red for sugars (needs heating in a water bath), Biuret reagent goes purple for proteins, and the ethanol test makes lipids go cloudy.
Remember: Benedict's test is quantitative - different sugar concentrations give different colours from green (low) to brick red (high).
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Enzyme Activity and Growing Microorganisms
Testing pH effects on amylase shows how enzymes work best at specific conditions. You'll mix starch, amylase, and different pH buffers, then test drops with iodine every 30 seconds. When the iodine stops turning blue-black, all the starch has been broken down.
The optimum pH might fall between your test values, so don't be surprised if your results aren't perfectly clear-cut. Timing every 30 seconds gives approximate results, and colour changes can be gradual.
Growing microorganisms requires aseptic technique to prevent contamination. Sterilise everything with flame, tape petri dishes so they can't fall open, and incubate upside down at 25°C to stop harmful bacteria thriving.
Safety first: 25°C prevents dangerous pathogens from growing, whilst higher temperatures in schools could create health risks.
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Antibiotics and Photosynthesis Experiments
Testing antibiotic effectiveness uses the same sterile techniques but adds filter paper discs soaked in different antibiotics. The zone of inhibition (clear area where bacteria can't grow) shows which antibiotic works best. Calculate the area using πr² to compare effectiveness properly.
Photosynthesis experiments measure oxygen bubble production from pondweed at different light distances. Use LED lights to avoid heat affecting your results, and sodium hydrogen carbonate solution to provide plenty of CO₂.
Count bubbles produced in one minute, but be aware this method has limitations - bubbles come too fast and aren't uniform sizes. Better results come from measuring oxygen volume with a gas syringe.
Key insight: When you double the distance from the light, bubble production drops by four times - this demonstrates the inverse square law of light intensity.
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Understanding Light Intensity and Distance
The relationship between distance and light intensity follows a predictable pattern that's crucial for your exams. As distance increases, light intensity decreases dramatically - specifically following the inverse square law.
This means if you move your pondweed twice as far from the light source, it receives four times less light energy. Consequently, photosynthesis rate drops by the same factor, producing far fewer oxygen bubbles.
Understanding this relationship helps explain why plants grow differently at various distances from light sources, and why measuring precise distances matters in your experiments.
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.
3
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Mock Exam
Quiz
Flashcards
Essay
Similar content
Cell Biology Essentials
Explore key concepts in cell biology, including active transport, cell specialization, and microscopy techniques. This summary covers essential processes like osmosis, diffusion, and the cell cycle, providing a comprehensive overview for AQA Combined Science students. Ideal for exam preparation and understanding fundamental biological principles.
Biology10
Osmosis in Potatoes Experiment
Explore the osmosis process through a hands-on potato experiment. This practical guide details the steps to investigate how different sucrose concentrations affect potato mass, including calculations for percentage change. Ideal for GCSE Biology students and anyone studying diffusion, osmosis, and tonicity concepts.
Biology12
Essential Biology Practicals
Explore key required practicals for Biology Paper 1, including microscopy techniques, osmosis experiments, photosynthesis investigations, and food tests. This comprehensive guide covers enzyme activity, carbohydrate testing, and the effects of pH on amylase, providing essential insights for your studies. Ideal for students preparing for exams.
Biology10
Osmosis Explained
Explore the process of osmosis, including the movement of water across partially permeable membranes, and the effects on plant and animal cells in different solutions. This summary covers key concepts such as hypertonic and hypotonic solutions, plasmolysis, and the structural differences between plant and animal cells. Ideal for biology students preparing for exams.
Biology8
GCSE triple biology paper 1 - B1
biology paper 1 higher topic B1 (cell structure and transport)
Biology9
Cell Structure Insights
Explore key exam questions and concepts related to cell structure, including human and plant cells, cellular processes, and the roles of organelles like ribosomes and mitochondria. This summary covers essential topics for understanding cellular organization and function, ideal for exam preparation.
Biology9
Most popular content: Diffusion and Osmosis
Most popular content in Biology
Most popular content
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.6/5
App Store
4.7/5
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 Knowunity AI. 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 Knowunity AI. 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