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22 Dec 2025
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High School Biology Study Notes
studycute
@studycuteandstaysmart
1 / 6
Getting Started with Biology
Biology is the fascinating study of life in all its forms. This subject covers loads of essential topics that help you understand how living things function and survive.
Your key revision areas include diet and nutrition (what keeps us healthy), anatomy (how our bodies work), and genetics (how traits pass from parents to offspring). You'll also dive into cell biology, learning about both simple prokaryotic cells and complex eukaryotic cells.
The practical side is brilliant too - you'll learn how to grow microorganisms safely in the lab and explore biodiversity to understand the amazing variety of life on Earth.
Quick Tip: Biology connects to your everyday life more than you might think - from understanding why you need certain foods to stay healthy, to figuring out how your body actually works!
Cell Structure and Types
Plant and animal cells are the building blocks of life, but they're structured quite differently. Animal cells are eukaryotic (they have a proper nucleus) and contain key structures like the nucleus (control centre), cytoplasm , cell membrane (outer boundary), and mitochondria (powerhouses that make energy).
Plant cells share these features but have some extra bits that make them special. They've got a tough cell wall for protection, chloroplasts for making food through photosynthesis, and a large vacuole that helps keep the plant rigid and upright.
The big difference is that plant cells can make their own food using sunlight, whilst animal cells need to get their energy from eating other organisms. Both types work together in ecosystems to keep life going.
Remember: Think of cells like tiny factories - each part has a specific job to keep the whole thing running smoothly!
Diet and Nutrition Essentials
A balanced diet isn't just about eating your vegetables - it's about getting the right mix of nutrients your body actually needs. Carbohydrates from bread, potatoes, and pasta give you energy for daily activities, whilst lipids (fats) from nuts and dairy provide long-term energy storage and keep you warm.
Proteins are your body's building materials, found in eggs, meat, and fish - they help you grow and repair damaged tissues. Vitamins and minerals might be needed in tiny amounts, but they're absolutely crucial for keeping your body's processes running smoothly.
Don't forget about dietary fibre from fruits and vegetables (keeps your digestive system happy) and water (helps transport everything around your body). Malnutrition happens when this balance goes wrong, leading to problems like obesity, starvation, or deficiency diseases.
Key Point: Think of your diet like fuel for a car - you need the right mix to keep everything running at peak performance!
Food Testing Techniques
Learning to test for different nutrients in food is a brilliant practical skill that shows you exactly what's in your meals. The iodine test for starch is dead simple - just add a drop of iodine solution to your food sample, and if it turns from brown to blue-black, you've found starch.
Benedict's reagent reveals sugars when you heat the mixture in a water bath at 60°C for five minutes - a colour change from blue to orange or brick-red means sugar is present. For proteins, Biuret reagent does the trick, turning from blue to pink or purple when it detects protein.
The lipid test is a bit different - you mix your sample with ethanol, then add water. If you see a cloudy white emulsion forming, you've found lipids. These tests are dead useful for understanding what nutrients different foods actually contain.
Lab Tip: Always use different pipettes for each test to avoid contamination - mixing reagents can give you false results!
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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
High School Biology Study Notes
studycute
@studycuteandstaysmart
Biology is all about understanding life and how living things work - from the tiniest cells to complex ecosystems. You'll explore everything from what makes up a healthy diet to how cells are structured and how to test for different... Show more
Getting Started with Biology
Biology is the fascinating study of life in all its forms. This subject covers loads of essential topics that help you understand how living things function and survive.
Your key revision areas include diet and nutrition (what keeps us healthy), anatomy (how our bodies work), and genetics (how traits pass from parents to offspring). You'll also dive into cell biology, learning about both simple prokaryotic cells and complex eukaryotic cells.
The practical side is brilliant too - you'll learn how to grow microorganisms safely in the lab and explore biodiversity to understand the amazing variety of life on Earth.
Quick Tip: Biology connects to your everyday life more than you might think - from understanding why you need certain foods to stay healthy, to figuring out how your body actually works!
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
Cell Structure and Types
Plant and animal cells are the building blocks of life, but they're structured quite differently. Animal cells are eukaryotic (they have a proper nucleus) and contain key structures like the nucleus (control centre), cytoplasm , cell membrane (outer boundary), and mitochondria (powerhouses that make energy).
Plant cells share these features but have some extra bits that make them special. They've got a tough cell wall for protection, chloroplasts for making food through photosynthesis, and a large vacuole that helps keep the plant rigid and upright.
The big difference is that plant cells can make their own food using sunlight, whilst animal cells need to get their energy from eating other organisms. Both types work together in ecosystems to keep life going.
Remember: Think of cells like tiny factories - each part has a specific job to keep the whole thing running smoothly!
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
Diet and Nutrition Essentials
A balanced diet isn't just about eating your vegetables - it's about getting the right mix of nutrients your body actually needs. Carbohydrates from bread, potatoes, and pasta give you energy for daily activities, whilst lipids (fats) from nuts and dairy provide long-term energy storage and keep you warm.
Proteins are your body's building materials, found in eggs, meat, and fish - they help you grow and repair damaged tissues. Vitamins and minerals might be needed in tiny amounts, but they're absolutely crucial for keeping your body's processes running smoothly.
Don't forget about dietary fibre from fruits and vegetables (keeps your digestive system happy) and water (helps transport everything around your body). Malnutrition happens when this balance goes wrong, leading to problems like obesity, starvation, or deficiency diseases.
Key Point: Think of your diet like fuel for a car - you need the right mix to keep everything running at peak performance!
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
Food Testing Techniques
Learning to test for different nutrients in food is a brilliant practical skill that shows you exactly what's in your meals. The iodine test for starch is dead simple - just add a drop of iodine solution to your food sample, and if it turns from brown to blue-black, you've found starch.
Benedict's reagent reveals sugars when you heat the mixture in a water bath at 60°C for five minutes - a colour change from blue to orange or brick-red means sugar is present. For proteins, Biuret reagent does the trick, turning from blue to pink or purple when it detects protein.
The lipid test is a bit different - you mix your sample with ethanol, then add water. If you see a cloudy white emulsion forming, you've found lipids. These tests are dead useful for understanding what nutrients different foods actually contain.
Lab Tip: Always use different pipettes for each test to avoid contamination - mixing reagents can give you false results!
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!
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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Most popular content in Biology
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Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.9/5
App Store
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