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Exploring the World of Plant Biology

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Licsha Sothiraj

08/12/2025

Biology

Plant biology

505

8 Dec 2025

2 pages

Exploring the World of Plant Biology

user profile picture

Licsha Sothiraj

@icshaothiraj_jacd90n

Plant leaves are amazing living factories that need to be... Show more

# Leaf Structure

Transparent so that light can
pass through to the palisade
Layer

Help to reduce water loss
by evaporation

waxy cuticle

Leaf Structure and Plant Tissues

Ever wondered why leaves are see-through when you hold them up to light? The transparent epidermis (outer layer) lets sunlight pass straight through to where the magic happens - the palisade mesophyll tissue packed with chloroplasts right at the top.

The leaf's middle section, called mesophyll whichliterallyjustmeans"middleofleaf"scientistslovetheirfancynames!which literally just means "middle of leaf" - scientists love their fancy names!, has two parts. The palisade layer does most of the photosynthesis, whilst the spongy mesophyll below is full of air spaces that help gases like CO₂ and oxygen move around easily.

Plants are organised just like you are - they have organs (leaves, stems, roots) made of different tissues. The waxy cuticle prevents water loss, stomata (tiny holes) control gas exchange, and vascular bundles containing xylem and phloem act like the plant's transport system, delivering water and nutrients whilst taking away glucose.

Quick Tip: Remember that guard cells around each stoma can open and close these holes depending on environmental conditions - they're like tiny bouncers controlling what gets in and out!

# Leaf Structure

Transparent so that light can
pass through to the palisade
Layer

Help to reduce water loss
by evaporation

waxy cuticle

Transport Systems: Xylem, Phloem and Transpiration

Think of plants as having two separate transport networks - xylem carries water and minerals up from roots to leaves, whilst phloem moves sugars around the plant in both directions. This two-way sugar transport is called translocation.

Xylem tubes are like drinking straws made from dead cells joined end-to-end with no barriers between them. They're strengthened with lignin and create the transpiration stream - a constant flow of water from roots to leaves. Phloem tubes are living cells with small pores that transport dissolved sugars in a liquid called cell sap.

Transpiration is basically plants "sweating" - water evaporates from leaves, creating a shortage that pulls more water up through the xylem. Four factors speed this up: brighter light (stomata open wider), higher temperature (more energy for evaporation), better air flow (removes water vapour), and lower humidity (bigger concentration difference).

Lab Connection: You can measure transpiration using a potometer - as the plant takes up water, an air bubble moves along a scale, letting you calculate the rate of water uptake!



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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

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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

505

8 Dec 2025

2 pages

Exploring the World of Plant Biology

user profile picture

Licsha Sothiraj

@icshaothiraj_jacd90n

Plant leaves are amazing living factories that need to be perfectly designed to make food through photosynthesis whilst staying alive. Understanding how leaves are structured and how they transport materials is crucial for grasping how plants survive and thrive in... Show more

# Leaf Structure

Transparent so that light can
pass through to the palisade
Layer

Help to reduce water loss
by evaporation

waxy cuticle

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

Leaf Structure and Plant Tissues

Ever wondered why leaves are see-through when you hold them up to light? The transparent epidermis (outer layer) lets sunlight pass straight through to where the magic happens - the palisade mesophyll tissue packed with chloroplasts right at the top.

The leaf's middle section, called mesophyll whichliterallyjustmeans"middleofleaf"scientistslovetheirfancynames!which literally just means "middle of leaf" - scientists love their fancy names!, has two parts. The palisade layer does most of the photosynthesis, whilst the spongy mesophyll below is full of air spaces that help gases like CO₂ and oxygen move around easily.

Plants are organised just like you are - they have organs (leaves, stems, roots) made of different tissues. The waxy cuticle prevents water loss, stomata (tiny holes) control gas exchange, and vascular bundles containing xylem and phloem act like the plant's transport system, delivering water and nutrients whilst taking away glucose.

Quick Tip: Remember that guard cells around each stoma can open and close these holes depending on environmental conditions - they're like tiny bouncers controlling what gets in and out!

# Leaf Structure

Transparent so that light can
pass through to the palisade
Layer

Help to reduce water loss
by evaporation

waxy cuticle

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

Transport Systems: Xylem, Phloem and Transpiration

Think of plants as having two separate transport networks - xylem carries water and minerals up from roots to leaves, whilst phloem moves sugars around the plant in both directions. This two-way sugar transport is called translocation.

Xylem tubes are like drinking straws made from dead cells joined end-to-end with no barriers between them. They're strengthened with lignin and create the transpiration stream - a constant flow of water from roots to leaves. Phloem tubes are living cells with small pores that transport dissolved sugars in a liquid called cell sap.

Transpiration is basically plants "sweating" - water evaporates from leaves, creating a shortage that pulls more water up through the xylem. Four factors speed this up: brighter light (stomata open wider), higher temperature (more energy for evaporation), better air flow (removes water vapour), and lower humidity (bigger concentration difference).

Lab Connection: You can measure transpiration using a potometer - as the plant takes up water, an air bubble moves along a scale, letting you calculate the rate of water uptake!

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?

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Is Knowunity really free of charge?

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Most popular content: Xylem

Most popular content in Biology

Most popular content

English - inspector calls quotes and analysis

Quotes from every main character

English LiteratureEnglish Literature
10

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