NCERT Textbook: Morphology of Flowering Plants - Biology Class 11 - NEET

 Page 1


UNIT 2
The description of the diverse forms of life on earth was made only by
observation – through naked eyes or later through magnifying lenses
and microscopes. This description is mainly of gross structural features,
both external and internal. In addition, observable and perceivable
living phenomena were also recorded as part of this description. Before
experimental biology or more specifically, physiology, was established
as a part of biology, naturalists described only biology. Hence, biology
remained as a natural history for a long time. The description, by itself,
was amazing in terms of detail. While the initial reaction of a student
could be boredom, one should keep in mind  that the detailed description,
was utilised in the later day reductionist biology where living processes
drew more attention from scientists than the description of life forms
and their structure. Hence, this description became meaningful and
helpful in framing research questions in physiology or evolutionary
biology. In the following chapters of this unit, the structural organisation
of plants and animals, including the structural basis of physiologial or
behavioural phenomena, is described. For convenience, this description
of morphological and anatomical features is presented separately for
plants and animals.
STRUCTURAL ORGANISATION
IN PLANTS AND ANIMALS
Chapter 5
Morphology of
Flowering Plants
Chapter 6
Anatomy of Flowering
Plants
Chapter 7
Structural Organisation in
Animals
Rationalised 2023-24
Page 2


UNIT 2
The description of the diverse forms of life on earth was made only by
observation – through naked eyes or later through magnifying lenses
and microscopes. This description is mainly of gross structural features,
both external and internal. In addition, observable and perceivable
living phenomena were also recorded as part of this description. Before
experimental biology or more specifically, physiology, was established
as a part of biology, naturalists described only biology. Hence, biology
remained as a natural history for a long time. The description, by itself,
was amazing in terms of detail. While the initial reaction of a student
could be boredom, one should keep in mind  that the detailed description,
was utilised in the later day reductionist biology where living processes
drew more attention from scientists than the description of life forms
and their structure. Hence, this description became meaningful and
helpful in framing research questions in physiology or evolutionary
biology. In the following chapters of this unit, the structural organisation
of plants and animals, including the structural basis of physiologial or
behavioural phenomena, is described. For convenience, this description
of morphological and anatomical features is presented separately for
plants and animals.
STRUCTURAL ORGANISATION
IN PLANTS AND ANIMALS
Chapter 5
Morphology of
Flowering Plants
Chapter 6
Anatomy of Flowering
Plants
Chapter 7
Structural Organisation in
Animals
Rationalised 2023-24
KATHERINE ESAU was born in Ukraine in 1898. She  studied
agriculture in Russia and Germany and received her doctorate
in 1931 in United States. She reported in her early publications
that the curly top virus spreads through a plant via the food-
conducting or phloem tissue. Dr Esau’s Plant Anatomy published
in 1954 took a dynamic, developmental approach designed to
enhance one’s understanding of plant structure and an
enormous impact worldwide, literally bringing about a revival
of the discipline. The Anatomy of Seed Plants by Katherine Esau
was published in 1960. It was referred to as Webster’s of plant
biology – it is encyclopediac. In 1957 she was elected to the
National Academy of Sciences, becoming the sixth woman to
receive that honour. In addition to this prestigious award, she
received the National Medal of Science from President George
Bush in 1989.
When Katherine Esau died in the year 1997, Peter Raven,
director of Anatomy and Morphology, Missouri Botanical
Garden, remembered that she  ‘absolutely dominated’ the field
of plant biology even at the age of 99.
Katherine Esau
(1898 – 1997)
Rationalised 2023-24
Page 3


UNIT 2
The description of the diverse forms of life on earth was made only by
observation – through naked eyes or later through magnifying lenses
and microscopes. This description is mainly of gross structural features,
both external and internal. In addition, observable and perceivable
living phenomena were also recorded as part of this description. Before
experimental biology or more specifically, physiology, was established
as a part of biology, naturalists described only biology. Hence, biology
remained as a natural history for a long time. The description, by itself,
was amazing in terms of detail. While the initial reaction of a student
could be boredom, one should keep in mind  that the detailed description,
was utilised in the later day reductionist biology where living processes
drew more attention from scientists than the description of life forms
and their structure. Hence, this description became meaningful and
helpful in framing research questions in physiology or evolutionary
biology. In the following chapters of this unit, the structural organisation
of plants and animals, including the structural basis of physiologial or
behavioural phenomena, is described. For convenience, this description
of morphological and anatomical features is presented separately for
plants and animals.
STRUCTURAL ORGANISATION
IN PLANTS AND ANIMALS
Chapter 5
Morphology of
Flowering Plants
Chapter 6
Anatomy of Flowering
Plants
Chapter 7
Structural Organisation in
Animals
Rationalised 2023-24
KATHERINE ESAU was born in Ukraine in 1898. She  studied
agriculture in Russia and Germany and received her doctorate
in 1931 in United States. She reported in her early publications
that the curly top virus spreads through a plant via the food-
conducting or phloem tissue. Dr Esau’s Plant Anatomy published
in 1954 took a dynamic, developmental approach designed to
enhance one’s understanding of plant structure and an
enormous impact worldwide, literally bringing about a revival
of the discipline. The Anatomy of Seed Plants by Katherine Esau
was published in 1960. It was referred to as Webster’s of plant
biology – it is encyclopediac. In 1957 she was elected to the
National Academy of Sciences, becoming the sixth woman to
receive that honour. In addition to this prestigious award, she
received the National Medal of Science from President George
Bush in 1989.
When Katherine Esau died in the year 1997, Peter Raven,
director of Anatomy and Morphology, Missouri Botanical
Garden, remembered that she  ‘absolutely dominated’ the field
of plant biology even at the age of 99.
Katherine Esau
(1898 – 1997)
Rationalised 2023-24
The wide range in the structure of higher plants will never fail to fascinate
us. Even though the angiosperms show such a large diversity in external
structure or morphology, they are all characterised by presence of roots,
stems, leaves, flowers and fruits.
In chapters 2 and 3, we talked about classification of plants based
on morphological and other characteristics. For any successful attempt
at classification and at understanding any higher plant (or for that
matter any living organism) we need to know standard technical terms
and  standard definitions. We also need to know about the possible
variations in different parts, found as adaptations of the plants to their
environment, e.g., adaptions to various habitats, for protection,
climbing, storage, etc.
If you pull out any weed you will see that all of them have roots, stems
and leaves. They may be bearing flowers and fruits. The underground
part of the flowering plant is the root system while the portion above the
ground  forms the shoot system (Figure 5.1).
5.1 THE ROOT
In majority of the dicotyledonous plants, the direct elongation of the radicle
leads to the formation of primary root which grows inside the soil.
It bears lateral roots of several orders that are referred to as secondary,
tertiary, etc. roots. The primary roots and its branches constitute the
MORPHOLOGY OF FLOWERING PLANTS
CHAPTER  5
5.1 The Root
5.2 The Stem
5.3 The Leaf
5.4 The Inflorescence
5.5 The Flower
5.6 The Fruit
5.7 The Seed
5.8 Semi-technical
Description of a
Typical
Flowering Plant
5.9 Description of
Some Important
Families
Rationalised 2023-24
Page 4


UNIT 2
The description of the diverse forms of life on earth was made only by
observation – through naked eyes or later through magnifying lenses
and microscopes. This description is mainly of gross structural features,
both external and internal. In addition, observable and perceivable
living phenomena were also recorded as part of this description. Before
experimental biology or more specifically, physiology, was established
as a part of biology, naturalists described only biology. Hence, biology
remained as a natural history for a long time. The description, by itself,
was amazing in terms of detail. While the initial reaction of a student
could be boredom, one should keep in mind  that the detailed description,
was utilised in the later day reductionist biology where living processes
drew more attention from scientists than the description of life forms
and their structure. Hence, this description became meaningful and
helpful in framing research questions in physiology or evolutionary
biology. In the following chapters of this unit, the structural organisation
of plants and animals, including the structural basis of physiologial or
behavioural phenomena, is described. For convenience, this description
of morphological and anatomical features is presented separately for
plants and animals.
STRUCTURAL ORGANISATION
IN PLANTS AND ANIMALS
Chapter 5
Morphology of
Flowering Plants
Chapter 6
Anatomy of Flowering
Plants
Chapter 7
Structural Organisation in
Animals
Rationalised 2023-24
KATHERINE ESAU was born in Ukraine in 1898. She  studied
agriculture in Russia and Germany and received her doctorate
in 1931 in United States. She reported in her early publications
that the curly top virus spreads through a plant via the food-
conducting or phloem tissue. Dr Esau’s Plant Anatomy published
in 1954 took a dynamic, developmental approach designed to
enhance one’s understanding of plant structure and an
enormous impact worldwide, literally bringing about a revival
of the discipline. The Anatomy of Seed Plants by Katherine Esau
was published in 1960. It was referred to as Webster’s of plant
biology – it is encyclopediac. In 1957 she was elected to the
National Academy of Sciences, becoming the sixth woman to
receive that honour. In addition to this prestigious award, she
received the National Medal of Science from President George
Bush in 1989.
When Katherine Esau died in the year 1997, Peter Raven,
director of Anatomy and Morphology, Missouri Botanical
Garden, remembered that she  ‘absolutely dominated’ the field
of plant biology even at the age of 99.
Katherine Esau
(1898 – 1997)
Rationalised 2023-24
The wide range in the structure of higher plants will never fail to fascinate
us. Even though the angiosperms show such a large diversity in external
structure or morphology, they are all characterised by presence of roots,
stems, leaves, flowers and fruits.
In chapters 2 and 3, we talked about classification of plants based
on morphological and other characteristics. For any successful attempt
at classification and at understanding any higher plant (or for that
matter any living organism) we need to know standard technical terms
and  standard definitions. We also need to know about the possible
variations in different parts, found as adaptations of the plants to their
environment, e.g., adaptions to various habitats, for protection,
climbing, storage, etc.
If you pull out any weed you will see that all of them have roots, stems
and leaves. They may be bearing flowers and fruits. The underground
part of the flowering plant is the root system while the portion above the
ground  forms the shoot system (Figure 5.1).
5.1 THE ROOT
In majority of the dicotyledonous plants, the direct elongation of the radicle
leads to the formation of primary root which grows inside the soil.
It bears lateral roots of several orders that are referred to as secondary,
tertiary, etc. roots. The primary roots and its branches constitute the
MORPHOLOGY OF FLOWERING PLANTS
CHAPTER  5
5.1 The Root
5.2 The Stem
5.3 The Leaf
5.4 The Inflorescence
5.5 The Flower
5.6 The Fruit
5.7 The Seed
5.8 Semi-technical
Description of a
Typical
Flowering Plant
5.9 Description of
Some Important
Families
Rationalised 2023-24
58 BIOLOGY
Flower
Shoot
system
Root
system
Fruit
Bud
Stem
Leaf
Node
Internode
Primary
root
Secondary
root
{
Figure 5.2 Different types of roots : (a) Tap  (b) Fibrous  (c) Adventitious
(c) (b)
Figure 5.1  Parts of a flowering plant
Fibrous roots
Adventitious roots
Laterals
(a)
Main root
tap root system, as seen in the mustard
plant (Figure 5.2a). In monocotyledonous
plants, the primary root is short lived and
is replaced by a large number of roots.
These roots originate from the base of the
stem and constitute the fibrous root
system, as seen in the wheat plant (Figure
5.2b). In some plants, like grass,
Monstera and the banyan tree, roots arise
from parts of the plant other than the
radicle and are called adventitious roots
(Figure 5.2c). The main functions of the
root system are absorption of water and
minerals from the soil, providing a proper
anchorage to the plant parts, storing
reserve food material and synthesis of
plant growth regulators.
Rationalised 2023-24
Page 5


UNIT 2
The description of the diverse forms of life on earth was made only by
observation – through naked eyes or later through magnifying lenses
and microscopes. This description is mainly of gross structural features,
both external and internal. In addition, observable and perceivable
living phenomena were also recorded as part of this description. Before
experimental biology or more specifically, physiology, was established
as a part of biology, naturalists described only biology. Hence, biology
remained as a natural history for a long time. The description, by itself,
was amazing in terms of detail. While the initial reaction of a student
could be boredom, one should keep in mind  that the detailed description,
was utilised in the later day reductionist biology where living processes
drew more attention from scientists than the description of life forms
and their structure. Hence, this description became meaningful and
helpful in framing research questions in physiology or evolutionary
biology. In the following chapters of this unit, the structural organisation
of plants and animals, including the structural basis of physiologial or
behavioural phenomena, is described. For convenience, this description
of morphological and anatomical features is presented separately for
plants and animals.
STRUCTURAL ORGANISATION
IN PLANTS AND ANIMALS
Chapter 5
Morphology of
Flowering Plants
Chapter 6
Anatomy of Flowering
Plants
Chapter 7
Structural Organisation in
Animals
Rationalised 2023-24
KATHERINE ESAU was born in Ukraine in 1898. She  studied
agriculture in Russia and Germany and received her doctorate
in 1931 in United States. She reported in her early publications
that the curly top virus spreads through a plant via the food-
conducting or phloem tissue. Dr Esau’s Plant Anatomy published
in 1954 took a dynamic, developmental approach designed to
enhance one’s understanding of plant structure and an
enormous impact worldwide, literally bringing about a revival
of the discipline. The Anatomy of Seed Plants by Katherine Esau
was published in 1960. It was referred to as Webster’s of plant
biology – it is encyclopediac. In 1957 she was elected to the
National Academy of Sciences, becoming the sixth woman to
receive that honour. In addition to this prestigious award, she
received the National Medal of Science from President George
Bush in 1989.
When Katherine Esau died in the year 1997, Peter Raven,
director of Anatomy and Morphology, Missouri Botanical
Garden, remembered that she  ‘absolutely dominated’ the field
of plant biology even at the age of 99.
Katherine Esau
(1898 – 1997)
Rationalised 2023-24
The wide range in the structure of higher plants will never fail to fascinate
us. Even though the angiosperms show such a large diversity in external
structure or morphology, they are all characterised by presence of roots,
stems, leaves, flowers and fruits.
In chapters 2 and 3, we talked about classification of plants based
on morphological and other characteristics. For any successful attempt
at classification and at understanding any higher plant (or for that
matter any living organism) we need to know standard technical terms
and  standard definitions. We also need to know about the possible
variations in different parts, found as adaptations of the plants to their
environment, e.g., adaptions to various habitats, for protection,
climbing, storage, etc.
If you pull out any weed you will see that all of them have roots, stems
and leaves. They may be bearing flowers and fruits. The underground
part of the flowering plant is the root system while the portion above the
ground  forms the shoot system (Figure 5.1).
5.1 THE ROOT
In majority of the dicotyledonous plants, the direct elongation of the radicle
leads to the formation of primary root which grows inside the soil.
It bears lateral roots of several orders that are referred to as secondary,
tertiary, etc. roots. The primary roots and its branches constitute the
MORPHOLOGY OF FLOWERING PLANTS
CHAPTER  5
5.1 The Root
5.2 The Stem
5.3 The Leaf
5.4 The Inflorescence
5.5 The Flower
5.6 The Fruit
5.7 The Seed
5.8 Semi-technical
Description of a
Typical
Flowering Plant
5.9 Description of
Some Important
Families
Rationalised 2023-24
58 BIOLOGY
Flower
Shoot
system
Root
system
Fruit
Bud
Stem
Leaf
Node
Internode
Primary
root
Secondary
root
{
Figure 5.2 Different types of roots : (a) Tap  (b) Fibrous  (c) Adventitious
(c) (b)
Figure 5.1  Parts of a flowering plant
Fibrous roots
Adventitious roots
Laterals
(a)
Main root
tap root system, as seen in the mustard
plant (Figure 5.2a). In monocotyledonous
plants, the primary root is short lived and
is replaced by a large number of roots.
These roots originate from the base of the
stem and constitute the fibrous root
system, as seen in the wheat plant (Figure
5.2b). In some plants, like grass,
Monstera and the banyan tree, roots arise
from parts of the plant other than the
radicle and are called adventitious roots
(Figure 5.2c). The main functions of the
root system are absorption of water and
minerals from the soil, providing a proper
anchorage to the plant parts, storing
reserve food material and synthesis of
plant growth regulators.
Rationalised 2023-24
MORPHOLOGY OF FLOWERING PLANTS 59
5.1.1 Regions of the Root
The root is covered at the apex by a thimble-like
structure called the root cap     (Figure 5.3). . . . . It
protects the tender apex of the root as it makes
its way through the soil. A few millimetres above
the root cap is the region of meristematic
activity.  The cells of this region are very small,
thin-walled and with dense protoplasm. They
divide repeatedly. The cells proximal to this
region undergo rapid elongation and
enlargement and are responsible for the growth
of the root in length. This region is called the
region of elongation. The cells of the elongation
zone gradually differentiate and mature. Hence,
this zone, proximal to region of elongation, is
called the region of maturation.  From this
region some of the epidermal cells form very fine
and delicate, thread-like structures called root
hairs. These root hairs absorb water and
minerals from the soil.
Figure 5.3  The regions of the root-tip
5.2 THE STEM
What are the features that distinguish a stem from a root? The stem is the
ascending part of the axis bearing branches, leaves, flowers and fruits. It
develops from the plumule of the embryo of a germinating seed. The stem
bears nodes and internodes. The region of the stem where leaves are
born are called nodes while internodes are the portions between two nodes.
The stem bears buds, which may be terminal or axillary. Stem is generally
green when young and later often become woody and dark brown.
The main function of the stem is spreading out branches bearing
leaves, flowers and fruits. It conducts water, minerals and photosynthates.
Some stems perform the function of storage of food, support, protection
and of vegetative propagation.
5.3 THE LEAF
The leaf is a lateral, generally flattened structure borne on the stem. It
develops at the node and bears a bud in its axil. The axillary bud later
develops into a branch. Leaves originate from shoot apical meristems and
are arranged in an acropetal order. They are the most important vegetative
organs for photosynthesis.
Rationalised 2023-24