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Transport in Plants Class 11 Notes CBSE Biology Chapter 11 [Free PDF Download]

Last updated date: 23rd Apr 2024
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Revision Notes for CBSE Class 11 Biology Chapter 11 (Transport In Plants Notes) - Free PDF Download

The curriculum of class 11 contains introductory topics of different subjects. The biology syllabus includes some essential topic introduction for higher academic life. The Central Board of Higher Secondary Education (CBSE) has included three major branches of Biology in the class 11 syllabus. The syllabus includes an introduction of some topics of these branches such as Zoology, botany, and physiology. This chapter is about the transportation system of the plants. You should read the chapter sincerely. You can follow some additional notes for a better understanding of the topic. You can go through revision notes for class 11 biology chapter 11. The class 11 biology chapter 11 notes will be good exam preparation tools for you.

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Transport In Plants Notes Chapter Related Important Study Materials
It is a curated compilation of relevant online resources that complement and expand upon the content covered in a specific chapter. Explore these links to access additional readings, explanatory videos, practice exercises, and other valuable materials that enhance your understanding of the chapter's subject matter.

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Transport in Plants Basic Subjective Questions - Class 11 Revision Notes

Section–A (1 Mark Questions)

1. Define translocation.

Ans. Transport of food through phloem in plants is known as translocation.

2. What would be the pressure potential of a flaccid cell?

Ans. In a flaccid cell, there is no pressure exerted by the protoplast against the cell wall. Thus, the pressure potential would be zero.

3. Why is salt added in excess to pickles?

Ans. Salt is added to the pickles to prevent the growth of any microorganism. The salt makes the pickle solution hypertonic, thus any microorganism coming in contact would get plasmolysed due to exosmosis and killed. This prevents spoilage of pickles.

4. Which part of the root is related with the absorption of water? 

Ans. The responsibility of absorption of water and minerals is more specifically the function of the root hairs that are present in millions at the tips of the roots. They greatly increase the surface area for absorption.

5. Casparian strip is made of a substance that is impervious to water. Name this substance.

Ans. Casparian strips are waterproof bands, which run around the cell wall of endodermal cells in plants. Casparian strips are made of suberin which is impermeable to water.

Section–B (2 Mark Questions)

6. A well-watered potted herbaceous plant shows wilting in the afternoon of a dry sunny day. Give reasons.

Ans. During noon, the rate of transpiration becomes higher than the rate of water absorption by plants. It causes a loss of turgidity and leads to wilting.

7. Explain why pure water has maximum water potential.

Ans. Water potential quantifies the tendency of water to move from one part to the other during various cellular processes. It is denoted by the Greek letter Psi or Ψ. The water potential of pure water is always taken as zero at standard temperature and pressure. It can be explained in terms of the kinetic energy possessed by water molecules. When water is in liquid form, the movement of its molecules is rapid and constant. Pure water has the highest concentration of water molecules. Therefore, it has the highest water potential. When some solute is dissolved in water, the water potential of pure water decreases.

8. Xylem transport is unidirectional and phloem transport bi-directional. Justify.

Ans. During the growth of a plant, its leaves act as the source of food as they carry out photosynthesis. The phloem conducts the food from the source to the sink (the part of the plant requiring or storing food). During spring, this process is reversed as the food stored in the sink is mobilized toward the growing buds of the plant, through the phloem. Thus, the movement of food in the phloem is bidirectional (i.e., upward and downward). The transport of water in the xylem takes place only from the roots to the leaves. Therefore, the movement of water and nutrients in the xylem is unidirectional.

9. Describe the plant cell as an osmotic system.

Ans. The plant cell is surrounded by a cell membrane and a cell wall. The cell wall is freely permeable to water and substances in solution, hence is not a barrier to movement. In plants, the cells usually contain a large central vacuole, whose contents, the vacuolar sap, contribute to the solute potential of the cell. In plant cells, the cell membrane and the membrane of the vacuole, the tonoplast together are important determinants of movement of molecules in or out of the cell. Both these membranes are selectively-permeable in nature.

10. What are ‘aquaporins’? How does the presence of aquaporins affect osmosis? (Exemplar)

Ans. Aquaporins are integral membrane proteins. These form pores or channels in the membrane. The water can flow more rapidly through these pores to the inside of the cell, as compared to the process of diffusion. These are the plumbing systems of the cells. These selectively conduct water in and out of the cells, while preventing the passage of ions and other solutes.

11. State the chemical composition of xylem and phloem sap.

Ans. Xylem sap consists mainly of water and some solutes or mineral nutrients. Phloem sap mainly consists of water and sucrose, a kind of transport sugar which is a disaccharide. Other sugars, hormones, and amino acids are also found in the phloem sap of the plants.

Class 11 Biology Chapter 11 Notes Free PDF Download

Translocation refers to the process of transport in plants via xylem and phloem. It includes the transport of water, minerals, and solutes.

Means of Transport 

Plants have three primary modes of transportation: 

  • Diffusion is the most common mode of plant transport. It is defined as the movement of molecules from a high concentration region to a low concentration region without the use of energy. As a result, diffusion is a passive process. The rate of diffusion is affected by the concentration gradient, temperature, and pressure.

  • Facilitated diffusion is a transport process facilitated by proteins known as permeases. It is a passive process as well. Transport reaches its maximum when all of the protein available for transport is saturated. It is a specific process that only allows certain molecules to pass through. Porins and aquaporins are proteins that aid in the process of facilitated diffusion. Porins are pores found in cell organelles such as mitochondria and plastids, as well as in some bacteria. Aquaporins are water channels that transport molecules of water.

Passive Transport

Passive Transport

The following process can result in facilitated diffusion:

  • Symport: The transport of multiple molecules in the same direction.

  • Antiport: The movement of molecules in the opposite direction.

  • Uniport: The movement of single molecules in any direction.

Types of Transport

Types of Transport

Active Transport in Plants 

The transport of molecules necessitates the expenditure of energy. It can transport solutes from a low concentration region to a high concentration region and vice versa. Active transport is facilitated by membrane proteins. It is a specific mode of solute transport.

Active transport in plants

Active transport in plants

Plant Water Relations 

Water is required for the growth of plants. However, too much or too little water is harmful to the plants. The process by which terrestrial plants lose some of their water from their aerial parts in the form of water vapor is known as transpiration. 

Water Potential 

Water potential is a measure of water's potential energy. The water potential of the cell is determined by solute potential and pressure potential. The highest water potential is found in pure water. Water always moves from a higher to lower water potential. The potential of water is denoted by the symbol psi or ψ. Pascals is the unit of measurement for water potential.

Water potential

Water potential

When a solute is added to pure water, the water potential falls to a negative value. This is referred to as solute potential. It is denoted by the symbol ψ\[_{s}\] Water potential increases when pressure exceeds atmospheric pressure in the case of pure water. Water moves from a region of high water potential to a region of low water potential, or from a dilute solution to a concentrated solution, as shown in the diagram above.

When water enters the plant cell, pressure builds up against the cell wall, making it more turgid. This increases the potential for pressure. As a result, the following is the relationship between water potential (ψ), solute potential ψ\[_{s}\], and pressure potential (ψ\[_{p}\]):

ψ = ψ\[_{p}\] + ψ\[_{s}\]


It is defined as the process of water molecules moving across a semi-permeable membrane. The movement of water is influenced by the concentration gradient and the pressure gradient.

Water molecules move until an equilibrium is reached between the two solutions. Osmotic pressure is the pressure applied to prevent the net movement of solute molecules across the membrane. Osmosis is required for the movement of molecules across membranes such as ions, proteins, and polysaccharides. 




The behavior of plant cells in relation to the external medium is subject to change. If the osmotic potential of the plant cell matches that of the external medium, the solution is said to be isotonic. The solution is said to be hypertonic if the osmotic potential is greater outside the cell than inside the cell. When the solute potential inside the cell is greater than the solute potential outside the cell, the solution is said to be hypotonic.



A hypertonic solution causes water molecules to move outside the cell. The cell is now referred to as flaccid. When a cell is immersed in a hypotonic solution, water moves within the cell. The cell is described as turgid. Plasmolysis is the process by which protoplasm shrinks away from the cell wall when a plant cell is kept in a hypertonic solution. Water moves out of the cell as a result of being immersed in a hypertonic solution. This is referred to as plasmolysis.

Plasmolyzed Cell

Plasmolyzed Cell


Imbibition refers to the absorption of water by solids, which causes them to expand in size. The most common example of imbibition is the swelling of raisins when kept in water. This is regarded as diffusion because water moves from high concentration to low concentration, i.e. along the concentration gradient.

Long-Distance Transport of Water 

Long-distance water transport is the quickest mode of water transport. Water, food, and minerals are typically moved by bulk flow or mass flow. Mass flow occurs between two pressure-differentiated solutions.

Translocation refers to the movement of substances through the vascular tissues of plants. Xylem and phloem are vascular tissues. Xylem aids in the movement of water molecules from the roots to various parts of the plant. Phloem facilitates the movement of food from the leaves to other parts of the plant. 

Different Pathways of Water Absorption 

Water is absorbed by plants through their roots. Root hairs are responsible for the absorption of water and minerals from the soil. Water moves from the roots to various parts of the plant via two different pathways. These routes are as follows:

  • Apoplast Pathway 

It is concerned with the movement of water in non-living plant parts such as intercellular spaces and cell walls. This pathway is disrupted by the endodermis. The endodermis is protected from water movement by Casparian strips. It does not entail the movement of water across the cell membrane.

Apoplast pathway

Apoplast pathway

  • Symplast Pathway 

It is the movement of water through protoplasts via cell-to-cell connections known as plasmodesmata. It aids in direct cytoplasm-to-cytoplasm movement. This process is slower than the apoplastic pathway of water movement.

Some plants, such as Pinus, have different structures for water absorption called Mycorrhiza. Mycorrhiza is fungal associations that occur between fungi and the roots of higher plants. It is a symbiotic relationship between the fungus and the plant roots. The fungal hyphae aid in the absorption of mineral ions and water from the soil, whereas the roots supply sugars and N-containing compounds to plant roots.

Water Movement up the Plant 

  • Root pressure occurs when ions present in the soil are actively transported into the vascular tissues of the roots, resulting in positive pressure inside the roots.

  • Transpiration pull occurs when ions present in the soil are actively transported into the vascular tissues of the roots, resulting in positive pressure inside the roots. This pressure is referred to as the root pressure, and it is responsible for the upward movement of water. When a stem is cut horizontally from the base, root pressure is measured. From the cut stem, a liquid will ooze out. The effect of root pressure can also be seen at night. Excess water in the form of water droplets is observed near the tips of the leaves when the rate of evaporation is low. This is referred to as guttation.

  • The driving force for water's upward movement is transpiration pull. Dixon and Jolly proposed the cohesion-tension theory to explain the upward movement of water in plants. The attraction between water molecules is referred to as cohesion. The attraction between water molecules and other polar molecules is referred to as adhesion. Surface tension is another property that promotes transpiration pull. The attraction between water molecules in the liquid phase is referred to as surface tension. Water is lost during transpiration, causing a negative pressure in the xylem vessels. This is referred to as transpiration pull.


Transpiration is the loss of water from leaves in the form of water vapor through stomata. Stomata are small openings in the leaves that open during the day and close at night.

Factors Influencing Transpiration

  • Elevated temperatures increase the rate of transpiration.

  • A larger surface area increases the rate of evaporation; high humidity decreases the rate of evaporation, and wind speed increases the rate of evaporation.

Mineral Nutrient Absorption and Transport

Minerals are absorbed by plants both passively and actively. The majority of the transport occurs actively because ions are charged and cannot cross the membrane without expending energy. ATP is used to provide energy. Sucrose, the end product of photosynthesis, is transported from the source (where synthesis occurs, such as leaves) to the sink (organs that store food). Food or sucrose transport is bidirectional, as opposed to water transport, which is unidirectional.

For sugar translocation from source to sink, the pressure-flow hypothesis, mass flow hypothesis, or Munch hypothesis was proposed. This happens through the phloem. Sieve tubes, companion cells, and phloem parenchyma make up phloem. Food is actively moved from source to sink via sieve tubes and companion cells. Sugars move through the phloem starting at the source, where they are loaded into a sieve tube. The loading in sieve tubes produces a hypertonic environment, which allows water to enter the phloem. Because of the high osmotic pressure at the source, the food/sucrose moves towards the sink (with low osmotic pressure). As a result, it is possible to conclude that osmotic pressure drives the movement of food from the source to the sink.

Pressure Flow

Pressure Flow

Class 11 Biology Chapter 11 Notes Free PDF Download

Biology is an essential subject for the higher academic life of science students. You should read this subject carefully to have a great academic life in the future. You should read all the chapters of this subject with great concern. The entire biology syllabus is divided into three parts as Zoology, Botany, and Physiology. Chapter 11 is from the botany part. This chapter gives a clear concept of transportation in plants. It is a vital chapter of functional studies of plants. You should read the chapter thoroughly for a clear concept of the topic. You can read chapter notes and important questions of chapter 11. You can download the class 11 biology chapter 11 notes. The transport in plants class 11 revision notes will be beneficial for your exam preparation.


Importance of Transportation In Plants Class 11 Notes 

The science syllabus of class 11 contains some introductory topics. Also, the biology syllabus has some vital chapters of different biological branches. You have to read all the chapters thoroughly for great conceptual knowledge. It will help you in your higher academic career in biology. First of all, you have to read the entire chapter carefully. Then, you should start revising. In the revision session, you should practice important questions of this chapter and go through the transport in plants class 11 revision notes. Here, we have mentioned the importance of notes of chapter transport in plants class 11.

  •  The revision notes will be beneficial for your exam preparation.

  • The chapter notes of chapter 11 give you a clear topic insight.

  • It provides you with ready chapter notes as an exam preparation tool.

  • It gives an idea about the question pattern.

  • The Notes will help you in last-minute revision.


How to Download the Notes of Chapter 11 Biology Class 11

You have to complete reading chapter 11 of the biology syllabus first. After that, you should start your revision. For your revision, you need some chapter wise important questions and revision notes. The revision notes are available online for free. Different educational websites and applications provide revision notes for class 11 biology chapter 11. You can go to the download link and download the revision notes in pdf format.

FAQs on Transport in Plants Class 11 Notes CBSE Biology Chapter 11 [Free PDF Download]

1. What are the Chapter Names of Class 11 CBSE Biology?

Ans: The names of chapters are The Living World, Respiration in Plants, Morphology of Flowering Plants, Plant Growth and Development, Anatomy of Flowering Plants,  Locomotion and Movement, Digestion and Absorption, Structural Organisation in Animals, Breathing and Exchange of Gases, Cell The Unit of Life, Biomolecules, Body Fluids and Circulation, Cell Cycle and Cell Division, Transport in Plants, Biological Classification, Mineral nutrition, Plant Kingdom, Photosynthesis in Higher Plants, Animal Kingdom, Excretory Products and their Elimination, Neural Control and Coordination and Chemical Coordination and Integration.

2. What is the Importance of Transpiration in Plants?

Ans: You must note that transpiration plays a vital role in plants. Besides dispersing extra water from the aerial plant parts, transpiration also helps in keeping the cell turgid. Plus, the process also makes the leaf surface cool, aids in the growth and development of plants regulates the temperature of a plant and facilitates mineral movement from soil to different plant parts.

3. What is Meant by Facilitated Diffusion?

Ans: Also considered as a passive procedure, facilitated diffusion is one of the transport procedures that are brought by proteins termed as permeases. Transport reaches the highest level when the available protein is saturated, and this process allows only the passing of specific molecules. Two proteins that assist in facilitated diffusion are porins and aquaporins. Moreover, facilitated diffusion is possible through symport, antiport and uniport processes.

4. What Kind of Substances are usually transported in Plants and what are the Pathways for their Transport?

Ans: A wide variety of substances are usually transported in flowering plants. However, the most commonly transported substances include water, mineral nutrients, organic nutrients or food and plant growth regulators. The transport of water in plans is primarily carried out by conductive tissues and individual cells of the vascular system. The movement of water in plants which enters the root hairs and xylem through either apoplast or symplast pathways is guided by the water potential gradient. This is the manner in which water is carried from the roots to the stem and other parts of the plant. On the other hand, organic nutrients or food is transported in plants through the phloem. During transportation, the energy from ATP is utilized to generate an osmotic pressure that allows for movement of food from higher concentration to lower concentration.

5. What are the Two main Types of Diffusion Mechanisms Employed for Transport in Plants?

Ans: The different mechanisms of diffusion that are employed for transport in plants include: 

  • Simple Diffusion: This mechanism is employed for transporting over small distances or from cell to cell. The substances simply move from a region of high concentration to a region of low concentration in a random manner with no expenditure of energy. 

  • Facilitated Diffusion: This transport mechanism is aided by special proteins that allow certain substances that otherwise find it difficult to move. This type of mechanism also does not allow for energy expenditure but allows for the movement of substances from higher to lower concentration regions and vice versa. 

6. Are Gases transported in Plants? If yes, explain how.

Ans: Yes, gases are transported in plants along with water and organic nutrients. The primary receptor organs for the transport of gases in plants are the leaves. Leaves have specialised cells called the stomata which are enclosed by the guard cells. The opening and closing of guard cells surrounding the stomata responsible for the exchange and transport of gases such as oxygen and carbon dioxide in plants. The stomatal cells are also responsible for the evaporative loss of water by the plants. 

7. Why should you refer to CBSE Class 11 Chapter 11 Notes PDF?

Ans: The CBSE Class 11 Chapter 11 Transport in Plants Notes by Vedantu provide students with a crisp understanding of transport in plants and the various processes and mechanisms involved in the same. The notes of Chapter 11 have been prepared by the experts at Vedantu in order to guide the students through the chapter in a systematic way. The Class 11 Chapter Transport in Plants is an important topic for students preparing for the Board as well as various competitive exams. The Class 11 CH 11 Notes PDF are easily downloadable and students can utilise them for revision purposes before exams. 

8. Which are the best notes for Chapter 11 of Class 11 Biology?

Ans: Vedantu’s Revision Notes of Chapter 11 of Class 11 Biology are the notes books for students to follow to get good grades in their Class 11 Biology exam. These notes are designed by subject experts to fulfil the needs of the students. They can refer to these notes while preparing for their exam and get a mastery of the concepts. The language that is used in these notes is simple to comprehend so that they are not left behind on any concepts.

9. Is Chapter 11 of Class 11 Biology easy?

Ans: Everything is easy when one is confident with what they have learnt. For this, students must follow a routine and dedicate proper time to Chapter 11 of Class 11 Biology. They should try to follow this schedule regularly, to achieve the desired results. They should read the chapter thoroughly, and mark all the important points. Along with this, they should follow Vedantu’s Revision Notes for Chapter 11 of Class 11 Biology. These notes are a great resource for last-minute revision before the exam.

10. What are the different means of transport?


  • DIFFUSION - It is a passive movement from one part of the cell to another or from one cell to another. In this process, no energy is used. It is a slow process of molecules moving from a region of high concentration to low concentration.

  • FACILITATED DIFFUSION - It is the transport of molecules from high concentration regions to low concentration with the support of the transport molecule.

  • ACTIVE TRANSPORT - This type of transport uses energy to pump the molecules against the concentration gradient and is usually carried out with the help of membrane proteins.

11. What is transpiration?

Ans: Transpiration is the process by which plants give out excess water. Plants just require a limited amount of water for their survival, and so they give out the remaining excess water through the process of transpiration. It can be said to be a process of evaporation where the water is lost through the stomata. The student needs to read the chapter thoroughly to be able to understand the process and point out the different parts that take place in the process.

12. Why should we refer to the Revision Notes of Chapter 11 of Class 11 Biology?

Ans: The revision notes provide easy insight into the important topics of Chapter 11 of Class 11 Biology. These notes are designed by experts for the benefit of students. The revision notes make the learning process easier and stress-free and the language is simple so students don’t have a problem comprehending the concepts. The revision notes also come in handy while revising before the exam. Thus, they must follow these notes to secure good grades. Vedantu provides these revision note at free of cost on the Vedantu app and on the Vedantu website.