8. Transport in Plants (Part 1) (Cambridge IGCSE Biology 0610 for exams in 2023, 2024 and 2025)

Summary

This IGCSE study video explores the transport system in plants, focusing on the roles of xylem and phloem. It explains how xylem vessels, with lignin-strengthened walls, transport water and minerals upwards, while phloem carries food to non-photosynthesizing parts. The video also covers the identification of these tissues in plant sections and demonstrates water uptake and transport through an experiment with dyed water and celery, providing a visual understanding of the plant's vascular system.

Takeaways

• 🌿 The video is part of a series on the Cambridge IGCSE biology syllabus, focusing on 'Transport in Plants'.
• 🔁 Plants have a transport system for nutrients and water, essential for their growth and function.
• 💧 Xylem and phloem are the two main transport vessels in plants, responsible for moving water, minerals, and nutrients.
• 🚰 Xylem transports water and mineral ions from the roots to the rest of the plant and provides structural support.
• 🌱 The structure of xylem vessels is adapted for efficient water transport with continuous tubes and thickened walls with lignin.
• 🍬 Phloem transports food, such as sucrose and amino acids, from the leaves to non-photosynthesizing parts of the plant.
• 🔠 A mnemonic to remember the function of phloem is that it starts with 'ph', similar to the sound of 'fur', which is associated with food.
• 🌳 Vascular bundles, containing xylem and phloem, are found throughout the plant, including roots, stems, and leaves.
• 📐 In diagrams, xylem is typically depicted on the inside and phloem on the outside of a cross-section.
• 🌱 Root hairs are specialized cells that increase the surface area for water and mineral absorption from the soil.
• 🚰 The pathway of water in a plant includes absorption by root hair cells, movement through the cortex, and transport via xylem to leaves.
• 🎨 An experiment using food dyes in water can visually demonstrate the movement of water through the xylem vessels in plants.

Q & A

What is the main purpose of the transport system in plants?

The main purpose of the transport system in plants is to carry nutrients within the plant, including water from the soil to the stem and leaves, and to distribute the nutrients produced by photosynthesis to other regions of the plant like stems and roots.

What are the two types of transport vessels in plants?

The two types of transport vessels in plants are the xylem and the phloem.

What substances does the xylem transport and what is its additional function?

The xylem transports water and mineral ions from the roots to the stem and leaves, and it also provides structural support to the plant.

How is the structure of xylem vessels adapted to their function of transporting water?

The xylem vessels have no cell contents, are joined end to end with no cross walls, forming a long continuous tube, and their walls are thickened with lignin for strength and to prevent collapsing, allowing water to pass easily.

What substances does the phloem transport and to which parts of the plant?

The phloem transports food substances, such as sucrose and amino acids, made by the plant from photosynthesizing leaves to non-photosynthesizing regions in the roots and stem.

How can you remember which vessel carries food and which carries water?

You can remember by the first sound; 'phloem' starts with the sound 'fur' and it carries food, which also starts with the 'fur' sound, while 'xylem' carries water.

What are vascular bundles and where are they located in a plant?

Vascular bundles are the collective term for xylem and phloem vessels and are found throughout the root, stem, and leaves of a plant.

In a cross section of a root, where is the xylem located relative to the phloem?

In a cross section of a root, the xylem is located on the inside in the shape of an X, and the phloem is the surrounding green area.

What are root hairs and how do they contribute to water uptake?

Root hairs are long extensions found on root hair cells, which are specialized cells in the roots of plants adapted to absorb water and minerals from the soil. They increase the surface area for increased uptake of water and mineral ions.

What is the pathway of water from the root hair cells to the mesophyll cells?

Water first enters the root hair cells from the soil through osmosis, then passes into the root cortex cells, travels up the xylem in the stem, and finally enters the mesophyll cells in the leaves.

How can you visually demonstrate the pathway of water in the above-ground parts of a plant?

By placing a plant like celery into beakers of water, one plain and two with different food dyes, and then observing the cross sections of the celery stalks after a few hours in sunlight, you can see the specific areas highlighted by the dyes in the xylem vessels, indicating the pathway of water.

Outlines

00:00

🌿 Introduction to Plant Transport Systems

This paragraph introduces the educational channel IGCSE Study Buddy and its focus on revising biology topics from the Cambridge IGCSE syllabus. It emphasizes the importance of subscribing and liking the video for more content. The main topic discussed is the transport system in plants, particularly the role of xylem and phloem as transport vessels. The xylem's function is to transport water and mineral ions from the roots to the leaves and provide structural support, while the phloem carries food from the leaves to other parts of the plant. The structural adaptations of xylem, such as the absence of cell contents and the presence of lignin, are highlighted to explain how these features facilitate water transport and support.

05:01

🍃 Root Hair Cells and Water Uptake Mechanism

The second paragraph delves into the specifics of how plants absorb water and minerals through the root system. It describes the structure and function of root hair cells, which are specialized for increased absorption surface area, enhancing the uptake of water and minerals. The paragraph outlines the pathway of water movement from the soil, through root hair cells, into the root cortex, and eventually into the xylem vessels, which transport it to the leaves. An experiment involving celery and food dyes is suggested to visually demonstrate the water uptake and transport process in plants. The video concludes with an encouragement to subscribe for more educational content on biology.

Keywords

💡IGCSE

The International General Certificate of Secondary Education (IGCSE) is a globally recognized qualification for learners around the world. It is an important part of the curriculum in many schools and is the focus of the video, as it aims to help students revise biology topics specific to the IGCSE syllabus.

💡Transport in Plants

This is the main theme of the video, referring to the biological process by which plants move nutrients and water throughout their structures. It is crucial for the survival and growth of plants, and the video provides an overview of this process, specifically focusing on the roles of xylem and phloem.

💡Xylem

Xylem is a type of vascular tissue in plants that transports water and mineral ions from the roots to the rest of the plant. The video explains the structure of xylem vessels, highlighting their continuous tube-like form and the presence of lignin for support, which is essential for efficient water transport.

💡Phloem

Phloem is the vascular tissue responsible for transporting food, such as sucrose and amino acids, produced by photosynthesis in the leaves to other parts of the plant. The video uses a mnemonic to help remember its function, associating the 'fur' sound in 'phloem' with the transport of 'food.'

💡Vascular Bundles

Vascular bundles are the collective term for xylem and phloem tissues, which are integral to the transport system in plants. The video emphasizes the importance of identifying these structures in diagrams of plant sections, such as roots, stems, and leaves.

💡Root Hairs

Root hairs are specialized cells found in the roots of plants that increase the surface area for absorption of water and minerals from the soil. The video describes how root hairs are adapted to their function, with a focus on their role in enhancing the uptake of water and nutrients.

💡Osmosis

Osmosis is the process by which water moves from an area of higher water potential to an area of lower water potential. In the context of the video, it is the mechanism by which water enters the root hair cells from the soil, initiating the transport process within the plant.

💡Active Transport

Active transport is the process by which cells move substances against a concentration gradient, requiring energy. The video mentions this process in relation to the absorption of mineral ions by root hair cells, highlighting the importance of energy in nutrient uptake.

💡Lignin

Lignin is a complex organic polymer that provides structural support to plant tissues, particularly the xylem vessels. The video explains that lignin strengthens and supports the xylem, preventing it from collapsing, which is crucial for maintaining the integrity of the plant's transport system.

💡Mesophyll Cells

Mesophyll cells are the photosynthetic cells found in the interior of leaves. The video describes the pathway of water from the root, through the xylem, and finally into the mesophyll cells, where it is used in photosynthesis.

💡Food Dyes Experiment

The food dyes experiment is a practical demonstration used in the video to visually illustrate the pathway of water through the plant's xylem vessels. By placing celery in water with red and blue food dyes, the video shows how the dyes are transported and highlight the specific areas of the plant where water moves.

Highlights

Introduction to IGCSE study buddy for revising biology topics from the Cambridge IGCSE syllabus.

Emphasis on the importance of liking and subscribing for more biology revision videos.

Explanation of the transport system in plants for carrying nutrients and water.

Role of the stem and leaves in the transport of nutrients made during photosynthesis.

Introduction to xylem and phloem as transport vessels within the plant.

Function of xylem in transporting water and mineral ions and providing structural support.

Structural adaptations of xylem vessels for efficient water transport.

Role of lignin in strengthening xylem vessels.

Phloem's role in transporting food substances like sucrose and amino acids.

Mnemonic for remembering the function of phloem and xylem based on phonetics.

Identification of vascular bundles and their position in plant diagrams.

Positioning of xylem and phloem in root sections with a focus on root hair cells.

Adaptations of root hair cells for increased water and mineral absorption.

Pathway of water from root hair cells to mesophyll cells in leaves.

Demonstration of water uptake and transport using a celery and food dye experiment.

Observation of color changes in leaves indicating water absorption by the plant.

Conclusion of part one of the topic on plant transport with a call to subscribe for more revision.

Transcripts

hi everyone welcome to IGCSE study buddy

where you can revise biology topics from

the Cambridge IGCSE syllabus

if you are enjoying this video so far

please don't forget to hit the like

button and subscribe to my channel

this video summarizes part 1 of chapter

8 transport in plants

plants have a transport system to carry

nutrients within them

water from the soil is needed by the

stem and leaves

the nutrients that leaves make during

photosynthesis are needed by other

regions of the plant like stems and

roots

the xylem and phloem are both transport

vessels that help move substances around

the plant

the xylem transports water and mineral

ions from the roots to the stem and

leaves

it also provides structural support to

the plant

so how does the structure of xylem

vessels relate to their functions

the xylem tissues have no cell contents

that means there are no cell organelles

the cells are joined end to end with no

cross walls in between therefore it

forms a long continuous tube

these two structural adaptations allow

the xylem to form an uninterrupted tube

through which water can pass easily

the other adaptation is that the walls

of xylem vessels are thickened with a

substance called lignin

this helps to strengthen and support the

xylem vessels and stops them collapsing

inwards

the phloem transports food that is

sucrose and amino acids made by the

plant from photosynthesizing leaves to

non-photosynthesizing regions in the

roots and stem

so how I used to remember which tube

carried which was the first sound

phloem starts with the sound fur and so

it carries food which also starts with

the fur sound

the xylem and phloem vessels are

collectively called vascular bundles

vascular bundles are found throughout

the root stem and leaves

we are expected to be able to identify

in diagrams and images the position of

xylem and phloem as seen in sections of

roots stems and leaves of non-woody

dicotyledonous plants

let's first learn the position of the

xylem and phloem in sections of roots

in the diagram below the pink area in

the shape of an X is the xylem tissue

the surrounding green area is where the

phloem tissues are located

if you look closely at the real image on

the right you will notice the inner

xylem area and the outer phloem area

so if you are asked to identify the

xylem of phloem in a diagram showing a

cross section of a root stem or Leaf

just remember that the xylem is always

on the inside and the phloem is always

on the outside

next let's learn the position of xylem

and phloem in sections of stems

in this diagram the inner pink areas are

the xylem tissue

the outer green part of the oval shapes

are the phloem tissues

on the right you can see a real image of

the cross section of a stem

now let's learn where the xylem and

phloem tissues are located in the cross

section of a leaf

in the diagram the upper pink area is

the xylem and the lower green area is

the phloem

and on the right is a real image of the

cross section of a leaf

moving on to water uptake we know that a

plant absorbs water through their roots

let's first take a look at the cross

section of a root

so looking at the diagram in the center

you may see the xylem and the phloem

surrounded by the cortex

on the outer part you may notice long

extensions these are called rootyas and

they face the soil

the cells with these root hairs are

called root hair cells

a root hair cell is a specialized cell

found in roots of plants that is

specially adapted to absorb water and

minerals from the soil

so how are root hair cells adapted to do

their job their root has greatly

increased their surface area which

therefore increases the uptake of water

and mineral ions

it increases the rate of absorption of

Water by osmosis

and it increases the rate of absorption

of mineral ions by active transport

now let's learn about the pathway taken

by water through the root stem and leaf

water first enters the root hair cells

from the soil through osmosis

this happens because the soil water has

a higher water potential than the

cytoplasm of the router cell

from the root hair cells the water

passes into the root cortex cells

then the water travels into the xylem

where it travels up the stem to the

leaves entering the mesophyll cells

here's a simpler diagram to follow the

pathway of water from the root hair

cells to the root cortex cells to the

xylem and then the mesophyll cells

let's investigate using a stain the

pathway of water through the above

ground parts of a plant

place a plant like celery into a beaker

of water this is the control

in two other beakers Place celery in the

water mixed with food dyes red in one

and blue in the other

leave all three plants in sunlight for a

few hours

afterwards cut cross sections of the

celery stalks and observe

the one which was in plain water will

leave no stain

the other two stalks will show specific

areas highlighted by the dyes as seen in

the diagram showing that the water is

moving in specific vessels the xylem

whistles

we would be able to observe color

changes in the leaves as well showing

that water is being taken up by the

plant

so that concludes part one of topic 8

transporting plants

hope you found this video useful thank

you for watching and please don't forget

to subscribe to IGCSE study buddy for

more biology revision videos bye