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Responding to change (a2 only)
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Britain & the wider world: 1745 -1901
1l the quest for political stability: germany, 1871-1991
The cold war
Inter-war germany
Medieval period: 1066 -1509
2d religious conflict and the church in england, c1529-c1570
2o democracy and nazism: germany, 1918-1945
1f industrialisation and the people: britain, c1783-1885
1c the tudors: england, 1485-1603
2m wars and welfare: britain in transition, 1906-1957
World war two & the holocaust
2n revolution and dictatorship: russia, 1917-1953
2s the making of modern britain, 1951-2007
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Biology
4 Dec 2025
124
2 pages
Ly @userly
Ever wondered how massive trees get water from their roots to their highest leaves, or how sugar made... Show more
Plants face a massive challenge photosynthesis happens in the leaves, but they need water and nutrients from the soil. That's where their brilliant transport system comes in, using two types of tubes that work like a plant's circulatory system.
Translocation is the fancy name for how plants move sugar around using phloem tubes. These tubes are made of living cells with gaps between them, allowing a mixture of sugar and water (called cell sap) to flow freely. What's brilliant is that this transport can go both ways - up or down the plant depending on where the sugar is needed.
The sugar travels to two main destinations it's either stored somewhere in the plant for later use, or used immediately for energy. Think of phloem as the plant's food delivery service, making sure every part gets fed.
Key Point Phloem tubes are like two-way motorways for sugar transport in plants.
Right next to the phloem sits the xylem - completely different tubes made of dead cells with no ends, creating one long hollow pipe. These tubes are strengthened with lignin (like internal scaffolding) and have one job transport water and mineral ions upwards from roots to leaves.
Transpiration is the process that drives this water transport system. When leaves lose water through evaporation (which happens because stomata must open to absorb CO₂), the xylem replaces that lost water. It's like a constant stream flowing upwards, called the transpiration stream.
The rate of transpiration isn't constant - it changes based on environmental conditions. Temperature increases transpiration because hot water evaporates faster. Bright light also speeds it up since photosynthesis requires open stomata.
Air flow increases transpiration by blowing water molecules away, whilst high humidity slows it down because the air is already full of water vapour. Understanding these factors helps explain why plants wilt on hot, dry days but perk up in cooler, humid conditions.
Remember Xylem is like a one-way lift system, always moving water upwards from roots to leaves.
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
7
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the process of transpiration in plants, including the roles of stomata, osmosis, and cohesion-tension theory. This summary covers how water moves through the plant, the significance of water potential, and the mechanisms controlling water loss. Ideal for A Level Biology students.
BiologyExplore the essential processes of transpiration and translocation in plants. This summary covers the roles of xylem and phloem, the movement of water, minerals, and sugars, and the factors influencing transpiration rates, including light intensity, temperature, air flow, and humidity.
BiologyExplore the intricacies of the circulatory system, including heart structure, blood flow, and treatments for coronary heart disease. Additionally, delve into plant transport mechanisms, focusing on xylem and phloem functions, transpiration, and adaptations for efficient gas exchange. This summary covers key concepts essential for understanding both mammalian and plant systems.
BiologyExplore the essential processes of photosynthesis and plant transport systems in this detailed study note. Understand how plants convert light energy into glucose, the role of chlorophyll, and the factors affecting photosynthesis rates. Learn about xylem and phloem functions, transpiration, and the adaptations of plant leaves for optimal photosynthesis. Ideal for GCSE (Edexcel) Combined Science Biology students.
BiologyExplore the plant transport system, focusing on the roles of xylem and phloem in water and nutrient transport. This summary covers key concepts such as vascular bundles, one-way water transport, and the two-way flow of sugars, essential for understanding plant biology. Ideal for GCSE Biology students preparing for exams.
BiologyExplore key concepts in immunology, plant structure, and physiological processes. This summary covers the immune response, circulatory and digestive systems, monoclonal antibodies, and plant transport mechanisms, including xylem and phloem. Ideal for students preparing for higher-tier biology exams.
BiologyQuotes from every main character
English LiteratureApp Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Ly
@userly
Ever wondered how massive trees get water from their roots to their highest leaves, or how sugar made in leaves travels to feed the entire plant? Plants have their own transport system that's actually quite clever - and understanding it... Show more
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Plants face a massive challenge: photosynthesis happens in the leaves, but they need water and nutrients from the soil. That's where their brilliant transport system comes in, using two types of tubes that work like a plant's circulatory system.
Translocation is the fancy name for how plants move sugar around using phloem tubes. These tubes are made of living cells with gaps between them, allowing a mixture of sugar and water (called cell sap) to flow freely. What's brilliant is that this transport can go both ways - up or down the plant depending on where the sugar is needed.
The sugar travels to two main destinations: it's either stored somewhere in the plant for later use, or used immediately for energy. Think of phloem as the plant's food delivery service, making sure every part gets fed.
Key Point: Phloem tubes are like two-way motorways for sugar transport in plants.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Right next to the phloem sits the xylem - completely different tubes made of dead cells with no ends, creating one long hollow pipe. These tubes are strengthened with lignin (like internal scaffolding) and have one job: transport water and mineral ions upwards from roots to leaves.
Transpiration is the process that drives this water transport system. When leaves lose water through evaporation (which happens because stomata must open to absorb CO₂), the xylem replaces that lost water. It's like a constant stream flowing upwards, called the transpiration stream.
The rate of transpiration isn't constant - it changes based on environmental conditions. Temperature increases transpiration because hot water evaporates faster. Bright light also speeds it up since photosynthesis requires open stomata.
Air flow increases transpiration by blowing water molecules away, whilst high humidity slows it down because the air is already full of water vapour. Understanding these factors helps explain why plants wilt on hot, dry days but perk up in cooler, humid conditions.
Remember: Xylem is like a one-way lift system, always moving water upwards from roots to leaves.
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
7
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the process of transpiration in plants, including the roles of stomata, osmosis, and cohesion-tension theory. This summary covers how water moves through the plant, the significance of water potential, and the mechanisms controlling water loss. Ideal for A Level Biology students.
BiologyExplore the essential processes of transpiration and translocation in plants. This summary covers the roles of xylem and phloem, the movement of water, minerals, and sugars, and the factors influencing transpiration rates, including light intensity, temperature, air flow, and humidity.
BiologyExplore the intricacies of the circulatory system, including heart structure, blood flow, and treatments for coronary heart disease. Additionally, delve into plant transport mechanisms, focusing on xylem and phloem functions, transpiration, and adaptations for efficient gas exchange. This summary covers key concepts essential for understanding both mammalian and plant systems.
BiologyExplore the essential processes of photosynthesis and plant transport systems in this detailed study note. Understand how plants convert light energy into glucose, the role of chlorophyll, and the factors affecting photosynthesis rates. Learn about xylem and phloem functions, transpiration, and the adaptations of plant leaves for optimal photosynthesis. Ideal for GCSE (Edexcel) Combined Science Biology students.
BiologyExplore the plant transport system, focusing on the roles of xylem and phloem in water and nutrient transport. This summary covers key concepts such as vascular bundles, one-way water transport, and the two-way flow of sugars, essential for understanding plant biology. Ideal for GCSE Biology students preparing for exams.
BiologyExplore key concepts in immunology, plant structure, and physiological processes. This summary covers the immune response, circulatory and digestive systems, monoclonal antibodies, and plant transport mechanisms, including xylem and phloem. Ideal for students preparing for higher-tier biology exams.
BiologyQuotes from every main character
English LiteratureApp Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Sociology