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Ruby-Coco
23/10/2025
Biology
Biology End Of Year 9 Topics
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23 Oct 2025
•
Year 9 Biology: Free Diffusion, Osmosis Notes & Exam Questions PDF
Ruby-Coco
@rubycoco08
1 / 6
Microscopes and Magnification
Understanding microscopes is essential for GCSE Biology microscopy exam questions AQA. Key components of a microscope include:
- Eyepiece lens
- Objective lenses
- Stage
- Light source
- Base
- Arm
- Fine focus
- Coarse focus
Vocabulary: The stage is where the microscope slide is placed for observation.
The magnification formula Biology is crucial for calculating image sizes:
Definition: Magnification = Image Size ÷ Real Size
This formula is essential for solving Biology magnification questions and answers PDF problems.
Stem Cells and Cell Functions
Stem cells are undifferentiated cells that can become any type of specialized cell.
Example: Embryonic stem cells and bone marrow stem cells are two types of stem cells.
Understanding cell functions is crucial for Active transport and cell functions study guide for year 9 biology free:
- Nucleus: Controls cell function and contains DNA
- Cell membrane: Regulates substance entry and exit
- Cytoplasm: Site of chemical reactions
- Mitochondria: Energy production through respiration
- Ribosomes: Protein synthesis
- Chloroplasts (in plant cells): Photosynthesis
- Vacuole (in plant cells): Storage of sap and sugars
- Cell wall (in plant cells): Structural support
Highlight: Mitochondria are crucial for active transport in animals, as they provide the necessary energy.
Prokaryotic and Eukaryotic Cells
Understanding the differences between prokaryotic and eukaryotic cells is essential for GCSE Biology microscopy exam questions AQA.
Prokaryotic cells:
- Size: 0.1-5.0 micrometers
- Examples: Bacteria
- Lack mitochondria and chloroplasts
- May contain plasmids for genetic information sharing
Eukaryotic cells:
- Size: 10-100 micrometers
- Found in plants, animals, fungi, and protists
- Contain organelles like mitochondria and chloroplasts
Vocabulary: Plasmids are small rings of DNA found in some prokaryotic cells.
This information is crucial for understanding Active transport bbc Bitesize and Osmosis bbc Bitesize ks3 concepts, as well as preparing for Diffusion, osmosis and active transport GCSE Exam Questions.
Diffusion and Osmosis
Diffusion is the gradual movement of particles from areas of high concentration to areas of low concentration. This natural process occurs in both solutions and gases.
Definition: Diffusion is the spreading out of particles from an area of higher concentration to an area of lower concentration.
Factors affecting diffusion rate include:
- Concentration gradient
- Temperature
Example: Perfume diffusing through a room demonstrates gas diffusion.
Osmosis is a specific type of diffusion involving water molecules.
Definition: Osmosis is the movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration.
Key points about osmosis:
- Occurs through a partially permeable membrane
- Water molecules pass in both directions
- Net flow is towards the stronger solution
Highlight: Osmosis is a passive process, meaning it doesn't require energy.
Active transport is the movement of particles against a concentration gradient.
Definition: Active transport is the movement of particles from a low concentration to a high concentration, requiring energy from mitochondria.
This process is crucial for various biological functions and is powered by cellular respiration.
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Anna
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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
Biology
23 Oct 2025
217
6 pages
Year 9 Biology: Free Diffusion, Osmosis Notes & Exam Questions PDF
Ruby-Coco @rubycoco08
End of Year 9 Biology: Diffusion, Osmosis, and Cell Functions
This comprehensive guide covers key concepts in biology for Year 9 students, including diffusion, osmosis, active transport,... Show more
Microscopes and Magnification
Understanding microscopes is essential for GCSE Biology microscopy exam questions AQA. Key components of a microscope include
- Eyepiece lens
- Objective lenses
- Stage
- Light source
- Base
- Arm
- Fine focus
- Coarse focus
Vocabulary The stage is where the microscope slide is placed for observation.
The magnification formula Biology is crucial for calculating image sizes
Definition Magnification = Image Size ÷ Real Size
This formula is essential for solving Biology magnification questions and answers PDF problems.
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
Stem Cells and Cell Functions
Stem cells are undifferentiated cells that can become any type of specialized cell.
Example Embryonic stem cells and bone marrow stem cells are two types of stem cells.
Understanding cell functions is crucial for Active transport and cell functions study guide for year 9 biology free
- Nucleus Controls cell function and contains DNA
- Cell membrane Regulates substance entry and exit
- Cytoplasm Site of chemical reactions
- Mitochondria Energy production through respiration
- Ribosomes Protein synthesis
- Chloroplasts (in plant cells) Photosynthesis
- Vacuole (in plant cells) Storage of sap and sugars
- Cell wall (in plant cells) Structural support
Highlight Mitochondria are crucial for active transport in animals, as they provide the necessary energy.
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Improve your grades
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By signing up you accept Terms of Service and Privacy Policy
Prokaryotic and Eukaryotic Cells
Understanding the differences between prokaryotic and eukaryotic cells is essential for GCSE Biology microscopy exam questions AQA.
Prokaryotic cells
- Size 0.1-5.0 micrometers
- Examples Bacteria
- Lack mitochondria and chloroplasts
- May contain plasmids for genetic information sharing
Eukaryotic cells
- Size 10-100 micrometers
- Found in plants, animals, fungi, and protists
- Contain organelles like mitochondria and chloroplasts
Vocabulary Plasmids are small rings of DNA found in some prokaryotic cells.
This information is crucial for understanding Active transport bbc Bitesize and Osmosis bbc Bitesize ks3 concepts, as well as preparing for Diffusion, osmosis and active transport GCSE Exam Questions.
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Diffusion and Osmosis
Diffusion is the gradual movement of particles from areas of high concentration to areas of low concentration. This natural process occurs in both solutions and gases.
Definition Diffusion is the spreading out of particles from an area of higher concentration to an area of lower concentration.
Factors affecting diffusion rate include
- Concentration gradient
- Temperature
Example Perfume diffusing through a room demonstrates gas diffusion.
Osmosis is a specific type of diffusion involving water molecules.
Definition Osmosis is the movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration.
Key points about osmosis
- Occurs through a partially permeable membrane
- Water molecules pass in both directions
- Net flow is towards the stronger solution
Highlight Osmosis is a passive process, meaning it doesn't require energy.
Active transport is the movement of particles against a concentration gradient.
Definition Active transport is the movement of particles from a low concentration to a high concentration, requiring energy from mitochondria.
This process is crucial for various biological functions and is powered by cellular respiration.
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
Sign up to see the contentIt's free!
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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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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