Anatomy of Flowering Plants Class 11 Biology: Tissue Systems and Dicot vs Monocot Anatomy

What Anatomy of Flowering Plants is about

Weightage: This chapter is part of Unit II, Structural Organization in Plants and Animals, which carries 10 of the 70 theory marks in the school annual exam together with Morphology of Flowering Plants and Structural Organisation in Animals.Source: CBSE Biology (044) syllabus 2026-27, Class XI course structure, Unit II Structural Organization in Plants and Animals

Key concepts

Epidermal tissue system: epidermis, cuticle, stomata and hairs

NCERT section 6.1.1 Epidermal Tissue System

The epidermal tissue system is the outer covering of the whole primary plant body. It includes epidermal cells, stomata and epidermal appendages (hairs and trichomes).

Epidermis: usually a single layer of elongated, tightly packed cells forming a continuous sheet. The cells are parenchymatous, with a thin lining of cytoplasm and a large vacuole. On the outside, aerial parts usually carry a thick waxy cuticle, which reduces water loss; roots have no cuticle.

Stomata occur in the epidermis of leaves and control transpiration and gas exchange.

• Each stoma has two guard cells around a stomatal pore. Guard cells are bean-shaped in most plants and dumb-bell-shaped in grasses.
• The guard cell wall facing the pore (inner wall) is heavily thickened, while the outer wall is thin; guard cells contain chloroplasts and control opening and closing.
• Nearby epidermal cells that differ in shape and size are subsidiary cells.
• Pore + guard cells + subsidiary cells = stomatal apparatus.

Hairs:

• Root hairs are unicellular outgrowths of root epidermal cells that absorb water and minerals.
• On the shoot, hairs are called trichomes; they are usually multicellular, branched or unbranched, soft or stiff, sometimes secretory, and help reduce water loss by transpiration.

Worked example

Which parts of the epidermal tissue system would you expect on (a) a young root and (b) a young shoot? How do root hairs and trichomes differ in structure and role? (3 marks)

Try it first, then show the solutionSolution

1. (a) Root: epidermis (epiblema) without a cuticle and without stomata, with root hairs. (b) Shoot: epidermis with a waxy cuticle, stomata (mainly on leaves) and trichomes. (1)
2. Root hairs are unicellular outgrowths of epidermal cells; trichomes are usually multicellular, branched or unbranched, and sometimes secretory. (1)
3. Root hairs absorb water and minerals from the soil; trichomes help reduce water loss by transpiration. (1)

Answer: Root: no cuticle or stomata, root hairs; shoot: cuticle, stomata, trichomes. Root hairs are unicellular and absorb; trichomes are multicellular and cut water loss.

Ground tissue system

NCERT section 6.1.2 The Ground Tissue System

The ground (fundamental) tissue system includes all tissues except the epidermis and the vascular bundles.

It is made of simple tissues: parenchyma, collenchyma and sclerenchyma.

• In primary stems and roots, parenchyma forms the cortex, pericycle, pith and medullary rays.
• Collenchyma (as hypodermis in dicot stems) gives flexible support; sclerenchyma (as hypodermis and bundle sheaths in monocot stems, and as pericycle patches in dicot stems) gives rigid support.
• In leaves, the ground tissue is the mesophyll: thin-walled cells containing chloroplasts, the site of photosynthesis.

Worked example

Name the components of the ground tissue system in (a) a dicot stem (b) a leaf. Which simple tissue makes up most of them? (2 marks)

Try it first, then show the solutionSolution

1. (a) Cortex (hypodermis, general cortex, endodermis), pericycle, medullary rays and pith. (1)
2. (b) Mesophyll (palisade and spongy parenchyma in dicots). Most are parenchyma. (1)

Answer: Cortex, pericycle, medullary rays, pith; mesophyll; mostly parenchyma.

Vascular tissue system and types of vascular bundles

NCERT section 6.1.3 The Vascular Tissue System

The vascular tissue system consists of the complex tissues xylem (conducts water and minerals) and phloem (conducts food). Together they form vascular bundles.

Open and closed bundles:

• Open: a strip of cambium lies between phloem and xylem, so the bundle can later form secondary xylem and phloem. Found in dicot stems.
• Closed: no cambium, so no secondary tissues form. Found in monocots.

Arrangement of xylem and phloem:

• Radial: xylem and phloem lie on different radii, alternating with each other, as in roots.
• Conjoint: xylem and phloem lie together on the same radius, as in stems and leaves. In conjoint bundles phloem is usually only on the outer side of xylem.

Position of protoxylem:

• Endarch: protoxylem (first-formed xylem) towards the centre (pith) and metaxylem outside: stems.
• Exarch: protoxylem towards the periphery and metaxylem towards the centre: roots.

Worked example

Distinguish between (a) open and closed vascular bundles and (b) radial and conjoint vascular bundles, with the plant organ in which each is found. (3 marks)

Try it first, then show the solutionSolution

1. (a) Open: cambium present between xylem and phloem, can form secondary tissues (dicot stem). Closed: no cambium (monocot stem and leaf). (1½)
2. (b) Radial: xylem and phloem on different radii, alternating (roots). Conjoint: xylem and phloem on the same radius, phloem usually outside (stems, leaves). (1½)

Answer: Open (dicot stem) vs closed (monocots); radial (roots) vs conjoint (stems, leaves).

Dicot root and monocot root

NCERT section 6.2.1 Dicotyledonous Root; 6.2.2 Monocotyledonous Root

Dicot root (T.S. of sunflower root, from outside inwards):
1. Epiblema (piliferous layer): outermost; many cells extend as unicellular root hairs.
2. Cortex: several layers of thin-walled parenchyma with intercellular spaces.
3. Endodermis: the innermost cortical layer; one layer of barrel-shaped cells with no intercellular spaces. Their radial and tangential walls carry bands of waterproof waxy suberin, the Casparian strips, which control what enters the vascular tissue.
4. Pericycle: a few layers of thick-walled parenchyma just inside the endodermis. Lateral roots and (during secondary growth) the vascular cambium arise here.
5. Vascular bundles: radial, with usually 2-4 xylem and phloem patches (diarch to tetrarch), exarch xylem. Parenchyma between xylem and phloem is conjunctive tissue. A cambium ring forms later between xylem and phloem.
6. Pith: small or inconspicuous.
The stele = all tissues inside the endodermis: pericycle, vascular bundles and pith.

Monocot root: similar in many ways (epidermis, cortex, endodermis, pericycle, radial bundles, pith), but:

• Usually more than six xylem bundles (polyarch).
• Pith is large and well developed.
• No secondary growth.

Worked example

In the T.S. of a sunflower root, name (a) the innermost cortical layer whose cells have waterproof bands on their radial and tangential walls (b) the layer from which lateral roots arise (c) the parenchyma lying between the xylem and phloem patches. Where does a cambium ring later develop? (3 marks)

Try it first, then show the solutionSolution

1. (a) Endodermis: barrel-shaped cells without intercellular spaces, with suberin Casparian strips. (1)
2. (b) Pericycle: a few layers of thick-walled parenchyma just inside the endodermis. (c) Conjunctive tissue. (1)
3. The cambium ring later develops between the xylem and the phloem. (1)

Answer: (a) endodermis (b) pericycle (c) conjunctive tissue; the cambium ring forms between xylem and phloem.

Dicot stem and monocot stem

NCERT section 6.2.3 Dicotyledonous Stem; 6.2.4 Monocotyledonous Stem

Dicot stem (T.S. of a young sunflower stem, outside inwards):
1. Epidermis: outer protective layer with a thin cuticle; may bear trichomes and a few stomata.
2. Cortex, in three zones:

• Hypodermis: a few layers of collenchyma below the epidermis, giving mechanical strength to the young stem.
• General cortex: rounded, thin-walled parenchyma with clear intercellular spaces.
• Endodermis: innermost cortical layer, rich in starch grains, so called the starch sheath.

3. Pericycle: inside the endodermis, above the phloem, as semi-lunar patches of sclerenchyma.
4. Medullary rays: a few layers of radially placed parenchyma between the bundles.
5. Vascular bundles: many, arranged in a ring (a key dicot stem feature); each is conjoint, open (with cambium) and has endarch protoxylem.
6. Pith: a large central region of rounded parenchyma with large intercellular spaces.

Monocot stem (e.g. maize):

• Hypodermis is sclerenchymatous.
• Many scattered vascular bundles, each surrounded by a sclerenchymatous bundle sheath.
• A large, conspicuous parenchymatous ground tissue (no distinct cortex, endodermis, pericycle or pith).
• Bundles are conjoint and closed; peripheral bundles are smaller than central ones.
• Phloem parenchyma is absent, and water-containing cavities are present within the bundles.

Worked example

Give four differences between the T.S. of a dicot stem and a monocot stem. (2 marks)

Try it first, then show the solutionSolution

1. Hypodermis: collenchymatous (dicot) vs sclerenchymatous (monocot); vascular bundles: in a ring vs scattered. (1)
2. Bundles: open (with cambium) vs closed with sclerenchymatous sheath; ground tissue: differentiated into cortex, pericycle, pith vs undifferentiated, with phloem parenchyma absent and water cavities in monocots. (1)

Answer: Hypodermis type, arrangement of bundles, open vs closed bundles, differentiated vs undifferentiated ground tissue.

Dorsiventral (dicot) leaf and isobilateral (monocot) leaf

NCERT section 6.2.5 Dorsiventral (Dicotyledonous) Leaf; 6.2.6 Isobilateral (Monocotyledonous) Leaf

A vertical section through the lamina shows epidermis, mesophyll and vascular system.

Dorsiventral (dicot) leaf:

• Epidermis: covers the upper (adaxial) and lower (abaxial) surfaces, with a clear cuticle. The lower (abaxial) epidermis usually has more stomata; the upper may have none.
• Mesophyll: chloroplast-rich parenchyma between the two epidermises, carrying out photosynthesis, with two kinds of cells:
• Palisade parenchyma: on the upper side, of long cells placed vertically and parallel to each other.
• Spongy parenchyma: below the palisade, extending to the lower epidermis; oval or round, loosely packed cells with many air spaces and cavities.
• Vascular system: bundles in the veins and midrib; their size depends on the size of the vein (veins vary in thickness in reticulate venation). Bundles are surrounded by a layer of thick-walled bundle sheath cells.

Isobilateral (monocot) leaf: similar in many ways, but:

• Stomata on both surfaces of the epidermis.
• Mesophyll is not differentiated into palisade and spongy parenchyma.
• In grasses, some adaxial epidermal cells along the veins become large, empty, colourless cells called bulliform cells. When they are full of water (turgid), the leaf surface is exposed; when they lose water (flaccid) in water stress, the leaf curls inwards, reducing water loss.
• Parallel venation shows as vascular bundles of nearly similar size (except in the main veins).

Worked example

Compare a dorsiventral and an isobilateral leaf in terms of stomata, mesophyll and vascular bundles. What are bulliform cells? (3 marks)

Try it first, then show the solutionSolution

1. Stomata: more on the lower surface (dorsiventral) vs on both surfaces (isobilateral). (1)
2. Mesophyll: palisade and spongy (dorsiventral) vs undifferentiated (isobilateral); bundles: of varying size with reticulate venation vs nearly similar size with parallel venation. (1)
3. Bulliform cells: large, empty, colourless adaxial epidermal cells in grasses; when they lose turgor, the leaf rolls inwards to cut water loss. (1)

Answer: Stomata, mesophyll and bundle size differ; bulliform cells roll the grass leaf in water stress.

Anatomy of Flowering Plants in real life

Each concept, met in an everyday situation. Read the situation, answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Topics in this chapter

• Dicot and Monocot Root and Stem Anatomy
• Tissue Systems and Vascular Bundles

Anatomy of Flowering Plants: key facts

Three tissue systems

$\text{epidermal}+\text{ground}+\text{vascular}$

Grouped by location and function.

Stele

$\text{stele}=\text{pericycle}+\text{vascular bundles}+\text{pith}$

Everything inside the endodermis.

Dicot root (outside in)

$\text{epiblema}\to \text{cortex}\to \text{endodermis}\to \text{pericycle}\to \text{radial bundles}\to \text{small pith}$

2-4 xylem patches; monocot root is polyarch with a large pith.

Dicot stem (outside in)

$\text{epidermis}\to \text{hypodermis (collenchyma)}\to \text{cortex}\to \text{starch sheath}\to \text{pericycle}\to \text{ring of bundles}\to \text{pith}$

Bundles conjoint, open, endarch.

Bundle types

$\text{radial (roots)};\text{conjoint open (dicot stem)};\text{conjoint closed (monocots)}$

Open = with cambium.

Anatomy of Flowering Plants: diagrams to practise

Practise each one on paper: draw it from the checklist, then tick off every label.

How the school exam asks Anatomy of Flowering Plants

The question patterns to expect, and the method that works for each.

Tricks to remember Anatomy of Flowering Plants

Short memory aids. Say each one aloud once, then use it on a question the same day.

• Every Child Eats Peanuts Very Plainly

  Dicot root layers: Epiblema, Cortex, Endodermis, Pericycle, Vascular bundles (radial), Pith.

  Use it when: Order of tissues in a root T.S.

• Ring = dicot, Rain of dots = monocot

  Vascular bundles in a ring: dicot stem; scattered like raindrops: monocot stem.

  Use it when: Identifying stem sections.

• Roots go Radial

  Radial bundles only in roots; conjoint in stems and leaves.

  Use it when: Bundle type questions.

• Pith: small in dicot root, big in monocot root

  Monocot roots are polyarch with a large pith; dicot roots have 2-4 xylem patches and little pith.

  Use it when: Root comparisons.

• Bulliform = Bend

  Bulliform cells let grass leaves bend (roll) in dry weather.

  Use it when: Monocot leaf questions.

Anatomy of Flowering Plants: exam-level solved questions

Ordered from exam level to HOTS. Cover the solution, write your own, then compare step by step.

Case-study practice (Section E style)

Read the situation, then answer every part. In a school exam set on the board pattern this is a 4-mark question split into 1 + 1 + 2 marks.

Where the marks are

How a typical answer is split into step marks. Show every step: a right final answer alone rarely earns full marks.

Where students lose marks in Anatomy of Flowering Plants

The slips examiners see most often, and what to write instead.

• ✗Mistake: Drawing conjoint bundles in a root

  Students copy the stem diagram.

  ✓Do this: Roots always have radial bundles with xylem and phloem on alternate radii.

  Usually costs: 1-2 marks in a diagram.

• ✗Mistake: Labelling the dicot stem endodermis as Casparian strip layer

  Root and stem endodermis are confused.

  ✓Do this: Casparian strips are emphasised in the root endodermis; in the dicot stem the endodermis is the starch sheath.

  Usually costs: ½ mark.

• ✗Mistake: Saying monocot stems have a pith and cortex

  Dicot features are assumed.

  ✓Do this: Monocot stems have undifferentiated ground tissue with scattered bundles.

  Usually costs: 1 mark.

• ✗Mistake: Putting more stomata on the upper surface of a dicot leaf

  Surface names are confused.

  ✓Do this: The lower (abaxial) surface usually has more stomata.

  Usually costs: ½ mark.

• ✗Mistake: Calling the pericycle of a dicot stem parenchymatous

  Root pericycle is generalised.

  ✓Do this: In the dicot stem the pericycle is semi-lunar patches of sclerenchyma; in the root it is thick-walled parenchyma.

  Usually costs: ½ mark.

NCERT exercise guide: Anatomy of Flowering Plants

What each exercise in the NCERT chapter tests, how to approach it, and a question of the same kind solved step by step. Questions here are written in our own words.

Practice questions on Anatomy of Flowering Plants

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

1. Q1 · 1 mark · MCQExam level

   Bulliform cells are found in:
   (a) dicot root (b) monocot leaf (c) dicot stem (d) monocot root

   Hint

   Grass leaves.

   Answer

   (b) monocot leaf

2. Q2 · 1 mark · MCQExam level

   Radial vascular bundles occur in:
   (a) stems (b) leaves (c) roots (d) petioles

   Hint

   Alternate radii.

   Answer

   (c) roots

3. Q3 · 2 marks · Very short answerExam level

   What are trichomes? Give two of their functions or features. (2 marks)

   Hint

   Shoot hairs.

   Answer

   Epidermal hairs on the shoot, usually multicellular (1); branched or unbranched, soft or stiff, sometimes secretory, and they help reduce water loss (1).

4. Q4 · 2 marks · Very short answerHarder exam level

   Why is the pericycle important in a root? (2 marks)

   Hint

   Branching and growth.

   Answer

   Lateral roots arise from the pericycle (1), and it contributes to the vascular cambium during secondary growth in dicot roots (1).

5. Q5 · 2 marks · Very short answerHarder exam level

   Give the functions of palisade and spongy parenchyma. (2 marks)

   Hint

   Light and gas.

   Answer

   Palisade: densely packed with chloroplasts, the main site of photosynthesis (1). Spongy: loosely arranged with air spaces for gas exchange and diffusion of CO₂ to photosynthetic cells (1).

6. Q6 · 2 marks · Very short answerHarder exam level

   Suppose you are given two unlabelled stem sections: one with bundles in a ring and a large pith, the other with scattered bundles in ground tissue. Which is which, and which plant could grow into a thick tree trunk? (2 marks)

   Hint

   Cambium.

   Answer

   Ring with pith: dicot stem; scattered bundles: monocot stem (1). The dicot, because its open bundles have cambium for secondary growth (1).

7. Q7 · 2 marks · Very short answerHarder exam level

   Explain why the cuticle is absent in roots but present on leaves and stems. (2 marks)

   Hint

   Absorption vs conservation.

   Answer

   Roots absorb water through their surface, so a waterproof layer would hinder absorption (1). Aerial parts lose water to the air, so a waxy cuticle reduces water loss (1).

8. Q8 · 3 marks · Short answerHarder exam level

   Name the three tissue systems of a dorsiventral leaf and the tissues or structures that make up each. (3 marks)

   Hint

   Epidermal, ground and vascular.

   Answer

   Epidermal: upper and lower epidermis with cuticle and stomata (1). Ground: mesophyll of palisade and spongy parenchyma (1). Vascular: xylem and phloem in the veins and midrib, surrounded by bundle sheath cells (1).

9. Q9 · 3 marks · Short answerHarder exam level

   Describe the monocot stem's vascular bundle in detail. (3 marks)

   Hint

   Sheath, closed, cavity.

   Answer

   Each bundle is conjoint and closed (no cambium), surrounded by a sclerenchymatous bundle sheath (1). Phloem is outside and xylem inside; phloem parenchyma is absent (1). A water-containing cavity lies in the xylem; peripheral bundles are smaller than central ones (1).

10. Q10 · 2 marks · Very short answerHOTS / competency

    Suppose a plant's leaves have stomata only on the upper surface and float flat on a pond. Suggest why, linking structure to habitat. (2 marks)

    Hint

    Lower surface touches water.

    Answer

    The lower surface is in contact with water, so stomata there could not exchange gases with air (1); stomata on the upper surface face the air, allowing gas exchange and transpiration (1).

11. Q11 · 5 marks · Long answerHOTS / competency

    (a) Compare the endodermis of a dicot root and a dicot stem. (b) Explain how the arrangement of tissues in a root suits absorption and conduction. (c) Why is the root's protoxylem exarch? (5 marks)

    Hint

    Casparian strips and short paths.

    Answer

    (a) Root: barrel-shaped cells with Casparian strips (suberin), controlling entry into the stele; stem: cells rich in starch (starch sheath), no emphasis on Casparian strips (2). (b) Root hairs increase absorbing area; thin-walled cortex lets water move inwards; endodermis regulates entry; radial bundles put xylem close to the pericycle for quick transfer (2). (c) Exarch protoxylem lies close to the periphery, giving the shortest path for water arriving from the cortex to enter the xylem (1).

12. Q12 · 1 mark · Assertion-reasonHOTS / competency

    Assertion (A): Vascular bundles in dicot stems are called open.
    Reason (R): Cambium is present between xylem and phloem, which can form secondary tissues.
    (a) Both A and R are true and R is the correct explanation of A.
    (b) Both A and R are true but R is not the correct explanation of A.
    (c) A is true but R is false.
    (d) A is false but R is true.

    Hint

    Definition of open.

    Answer

    (a)

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1. 1.What is anatomy?Show answer

   The study of the internal structure of plants.

2. 2.Name the three tissue systems.Show answer

   Epidermal, ground (fundamental) and vascular (conducting).

3. 3.What is a stomatal apparatus?Show answer

   The stomatal pore, guard cells and surrounding subsidiary cells together.

4. 4.Why is there no cuticle on roots?Show answer

   Roots must absorb water through their surface, so a waterproof cuticle would block uptake.

5. 5.What are Casparian strips made of?Show answer

   Suberin, a waterproof waxy substance on the radial and tangential walls of root endodermal cells.

6. 6.Where do lateral roots arise?Show answer

   From the pericycle.

7. 7.What is conjunctive tissue?Show answer

   Parenchyma lying between xylem and phloem in the root.

8. 8.Why is the dicot stem endodermis called a starch sheath?Show answer

   Its cells are rich in starch grains.

9. 9.What type of vascular bundles are found in a monocot stem?Show answer

   Conjoint and closed, scattered, each with a sclerenchymatous bundle sheath.

10. 10.What are bulliform cells?Show answer

    Large, empty, colourless epidermal cells on the upper side of grass leaves that make the leaf roll in water stress.

Quick revision checklist

The night before the exam: can you do each of these without looking?

• ☐Can you list the parts of the epidermal tissue system?
• ☐Can you draw a stoma with bean-shaped and dumb-bell-shaped guard cells?
• ☐Can you define open, closed, radial and conjoint bundles?
• ☐Can you list the dicot root layers in order from outside?
• ☐Can you give three differences between dicot and monocot roots?
• ☐Can you give four differences between dicot and monocot stems?
• ☐Can you describe palisade and spongy mesophyll?
• ☐Can you explain how bulliform cells roll a grass leaf?

Anatomy of Flowering Plants: frequently asked questions