Anatomy of Flowering Plants Class 11 Notes Biology Chapter 6

 Page 1


Points to Remember
Anatomy : Anatomy is the study of internal structure of organisms. Plant 
anatomy includes organisation and structure of tissues.
Tissue is a group is cells having a common origin and usually performing 
a common function.
There are two types of tissues (i) Meristematic (ii) Permanent
Meristematic tissues : The meristematic tissue is made up of the cells which 
have the capability to divide. Meristems in plants are restricted to a specialised 
regions and responsible to the growth of plants.
Meristems
      Apical meristem  Intercalary meristem        Lateral Meristem
? Occurs at  the tips of ? Occurs between ? Occurs in the mature
roots and shoots mature tissue region of roots and
shoots
? Primary meristem ? Primary meristem ? Secondary meristem
? Increase the length of ? Occur in grasses and ? Appears later than
plant regenerate parts primary meristem
removed by grazers and responsible for
secondary growth
 Axillary bud : The buds which are present in the axils of leaves (Consist  
of cells left behind from shoot apical meristem) and are responsible for forming 
branches of flowers.
Permanent tissues : The permanent tissues are derived from meristematic 
tissue, are composed of cells, which have lost the ability to divide and have become 
structurally and functionally specialised.
Page 2


Points to Remember
Anatomy : Anatomy is the study of internal structure of organisms. Plant 
anatomy includes organisation and structure of tissues.
Tissue is a group is cells having a common origin and usually performing 
a common function.
There are two types of tissues (i) Meristematic (ii) Permanent
Meristematic tissues : The meristematic tissue is made up of the cells which 
have the capability to divide. Meristems in plants are restricted to a specialised 
regions and responsible to the growth of plants.
Meristems
      Apical meristem  Intercalary meristem        Lateral Meristem
? Occurs at  the tips of ? Occurs between ? Occurs in the mature
roots and shoots mature tissue region of roots and
shoots
? Primary meristem ? Primary meristem ? Secondary meristem
? Increase the length of ? Occur in grasses and ? Appears later than
plant regenerate parts primary meristem
removed by grazers and responsible for
secondary growth
 Axillary bud : The buds which are present in the axils of leaves (Consist  
of cells left behind from shoot apical meristem) and are responsible for forming 
branches of flowers.
Permanent tissues : The permanent tissues are derived from meristematic 
tissue, are composed of cells, which have lost the ability to divide and have become 
structurally and functionally specialised.
Types of Permanent Tissue
Simple (i) Complex (ii)
    Parenchyma        Collenchyma Scierenchyma        Xylem    Phloem
Parenchyma : Living, thin walled isodiametric cells, with interceullar spaces, 
cell wall is made up of cellulose. It performs the functions like photosynthesis, 
storage, secretion.
Collenchyma : It is formed of living, closely packed cells. Its cells are 
thicknened at the corners due to depositon of celluose and pectin. It provide 
mechanical support to the growing parts of the plant. It is either found in 
homogenous layer or patches.
Sclerenchyma : It is formed of dead cells with thick and lignified walls. 
Provide mechanical support to organs. They have two types of cells : fibres and 
sclereids.
(a) Fibers—are thick walled,elongated and pointed cells.
(b) Sclereids—are spherical, oval or cylindrical, highly thickened dead cells 
with narrow lumen. Found in walls of nut, pulp of fruits like guava, seed coat of 
legumes and leaves of tea.
Xylem : Xylem consists of tracheids vessels, xylem fibres and xylem 
parenchyma. It conducts water and minerals from roots to other parts of plant.
(a) Tracheids—Tube like cells with thick and lignified walls and tapering 
ends; dead, without protoplasm.
(b) Vessel—long cylindrical structure made up of many cells with large 
central cavity, devoid of protoplasm. Present in angiosperms.
(c) Xylem fibres —highly thickened walls; with obliterated lumens; septate 
or aseptate.
(d) Xylem parenchyma—living and thin walled; cell walls made up 
cellulose, store food material in form of starch or fat.
Radial conduction of water takes place by ray parenchymatous cells
Protoxylem : The first formed primary xylem elements.
Metaxylem : The later formed primary xylem.
Endarch : Protoxylem lies towards the centre and metaxylem towards the 
periphery of the organ; in stem
Page 3


Points to Remember
Anatomy : Anatomy is the study of internal structure of organisms. Plant 
anatomy includes organisation and structure of tissues.
Tissue is a group is cells having a common origin and usually performing 
a common function.
There are two types of tissues (i) Meristematic (ii) Permanent
Meristematic tissues : The meristematic tissue is made up of the cells which 
have the capability to divide. Meristems in plants are restricted to a specialised 
regions and responsible to the growth of plants.
Meristems
      Apical meristem  Intercalary meristem        Lateral Meristem
? Occurs at  the tips of ? Occurs between ? Occurs in the mature
roots and shoots mature tissue region of roots and
shoots
? Primary meristem ? Primary meristem ? Secondary meristem
? Increase the length of ? Occur in grasses and ? Appears later than
plant regenerate parts primary meristem
removed by grazers and responsible for
secondary growth
 Axillary bud : The buds which are present in the axils of leaves (Consist  
of cells left behind from shoot apical meristem) and are responsible for forming 
branches of flowers.
Permanent tissues : The permanent tissues are derived from meristematic 
tissue, are composed of cells, which have lost the ability to divide and have become 
structurally and functionally specialised.
Types of Permanent Tissue
Simple (i) Complex (ii)
    Parenchyma        Collenchyma Scierenchyma        Xylem    Phloem
Parenchyma : Living, thin walled isodiametric cells, with interceullar spaces, 
cell wall is made up of cellulose. It performs the functions like photosynthesis, 
storage, secretion.
Collenchyma : It is formed of living, closely packed cells. Its cells are 
thicknened at the corners due to depositon of celluose and pectin. It provide 
mechanical support to the growing parts of the plant. It is either found in 
homogenous layer or patches.
Sclerenchyma : It is formed of dead cells with thick and lignified walls. 
Provide mechanical support to organs. They have two types of cells : fibres and 
sclereids.
(a) Fibers—are thick walled,elongated and pointed cells.
(b) Sclereids—are spherical, oval or cylindrical, highly thickened dead cells 
with narrow lumen. Found in walls of nut, pulp of fruits like guava, seed coat of 
legumes and leaves of tea.
Xylem : Xylem consists of tracheids vessels, xylem fibres and xylem 
parenchyma. It conducts water and minerals from roots to other parts of plant.
(a) Tracheids—Tube like cells with thick and lignified walls and tapering 
ends; dead, without protoplasm.
(b) Vessel—long cylindrical structure made up of many cells with large 
central cavity, devoid of protoplasm. Present in angiosperms.
(c) Xylem fibres —highly thickened walls; with obliterated lumens; septate 
or aseptate.
(d) Xylem parenchyma—living and thin walled; cell walls made up 
cellulose, store food material in form of starch or fat.
Radial conduction of water takes place by ray parenchymatous cells
Protoxylem : The first formed primary xylem elements.
Metaxylem : The later formed primary xylem.
Endarch : Protoxylem lies towards the centre and metaxylem towards the 
periphery of the organ; in stem
Exarch : Protoxylem toward periphery and metaxylem towards centre; in 
roots.
Phloem :Phloem consists of sieve tube elements, companion cells, phloem 
fibres and phloem parenchyma; Phloem transports the food material from leaves 
to various parts of the plant.
(a) Sieve tube elements :
? long tube like structures arranged longitudinally.
? associated with companion cells.
? end walls are perforated to form sieve plates.
? functions of sieve tubes are controlled by the nucleus of companion cells.
(b) Companion cells
? Specialised parenchymatous cells associated with sieve tube elements
? Connected with sieve tube elements by pit fields present between their
common longitudinal walls
? Help to maintain pressure gradient in sieve tubes.
(c)  Phloem Parenchyma
? made up of elongated, tapering cylindrical cells with dense cytoplasm and
nucleus.
? cell wall made of cellulose with pits through which plasmodesmatal
connections exist between cells.
? store food material.
(d)  Phloem fibers (bast fibers)
? are sclerenchymatous; absent in primary phloem but present in secondary
phloem.
? elongated, unbranched pointed, needle like apices with thick cell walls.
 Protophloem : First formed phloem with narrow sieve tubes.
  Metaphloem : Later formed phloem with bigger sieve tubes.
The Tissue System :
1. Epidermal tissue system : It includes cuticle, epidermis, epidermal hairs,
root hairs, trichomes and stomata.
The Tissue System :
(1) Epdiermal tissue system : It includes.
(a) Cuticle—Waxy thick layer outside epidermis, prevents the loss of water.
 (b) Epidermis : Outer most layer of primary plant body.
 (c) Epidermal hair : help in absorbing water and mineral from soil.
 (d) Trichomes : help in preventing water loss due to transpiration.
Page 4


Points to Remember
Anatomy : Anatomy is the study of internal structure of organisms. Plant 
anatomy includes organisation and structure of tissues.
Tissue is a group is cells having a common origin and usually performing 
a common function.
There are two types of tissues (i) Meristematic (ii) Permanent
Meristematic tissues : The meristematic tissue is made up of the cells which 
have the capability to divide. Meristems in plants are restricted to a specialised 
regions and responsible to the growth of plants.
Meristems
      Apical meristem  Intercalary meristem        Lateral Meristem
? Occurs at  the tips of ? Occurs between ? Occurs in the mature
roots and shoots mature tissue region of roots and
shoots
? Primary meristem ? Primary meristem ? Secondary meristem
? Increase the length of ? Occur in grasses and ? Appears later than
plant regenerate parts primary meristem
removed by grazers and responsible for
secondary growth
 Axillary bud : The buds which are present in the axils of leaves (Consist  
of cells left behind from shoot apical meristem) and are responsible for forming 
branches of flowers.
Permanent tissues : The permanent tissues are derived from meristematic 
tissue, are composed of cells, which have lost the ability to divide and have become 
structurally and functionally specialised.
Types of Permanent Tissue
Simple (i) Complex (ii)
    Parenchyma        Collenchyma Scierenchyma        Xylem    Phloem
Parenchyma : Living, thin walled isodiametric cells, with interceullar spaces, 
cell wall is made up of cellulose. It performs the functions like photosynthesis, 
storage, secretion.
Collenchyma : It is formed of living, closely packed cells. Its cells are 
thicknened at the corners due to depositon of celluose and pectin. It provide 
mechanical support to the growing parts of the plant. It is either found in 
homogenous layer or patches.
Sclerenchyma : It is formed of dead cells with thick and lignified walls. 
Provide mechanical support to organs. They have two types of cells : fibres and 
sclereids.
(a) Fibers—are thick walled,elongated and pointed cells.
(b) Sclereids—are spherical, oval or cylindrical, highly thickened dead cells 
with narrow lumen. Found in walls of nut, pulp of fruits like guava, seed coat of 
legumes and leaves of tea.
Xylem : Xylem consists of tracheids vessels, xylem fibres and xylem 
parenchyma. It conducts water and minerals from roots to other parts of plant.
(a) Tracheids—Tube like cells with thick and lignified walls and tapering 
ends; dead, without protoplasm.
(b) Vessel—long cylindrical structure made up of many cells with large 
central cavity, devoid of protoplasm. Present in angiosperms.
(c) Xylem fibres —highly thickened walls; with obliterated lumens; septate 
or aseptate.
(d) Xylem parenchyma—living and thin walled; cell walls made up 
cellulose, store food material in form of starch or fat.
Radial conduction of water takes place by ray parenchymatous cells
Protoxylem : The first formed primary xylem elements.
Metaxylem : The later formed primary xylem.
Endarch : Protoxylem lies towards the centre and metaxylem towards the 
periphery of the organ; in stem
Exarch : Protoxylem toward periphery and metaxylem towards centre; in 
roots.
Phloem :Phloem consists of sieve tube elements, companion cells, phloem 
fibres and phloem parenchyma; Phloem transports the food material from leaves 
to various parts of the plant.
(a) Sieve tube elements :
? long tube like structures arranged longitudinally.
? associated with companion cells.
? end walls are perforated to form sieve plates.
? functions of sieve tubes are controlled by the nucleus of companion cells.
(b) Companion cells
? Specialised parenchymatous cells associated with sieve tube elements
? Connected with sieve tube elements by pit fields present between their
common longitudinal walls
? Help to maintain pressure gradient in sieve tubes.
(c)  Phloem Parenchyma
? made up of elongated, tapering cylindrical cells with dense cytoplasm and
nucleus.
? cell wall made of cellulose with pits through which plasmodesmatal
connections exist between cells.
? store food material.
(d)  Phloem fibers (bast fibers)
? are sclerenchymatous; absent in primary phloem but present in secondary
phloem.
? elongated, unbranched pointed, needle like apices with thick cell walls.
 Protophloem : First formed phloem with narrow sieve tubes.
  Metaphloem : Later formed phloem with bigger sieve tubes.
The Tissue System :
1. Epidermal tissue system : It includes cuticle, epidermis, epidermal hairs,
root hairs, trichomes and stomata.
The Tissue System :
(1) Epdiermal tissue system : It includes.
(a) Cuticle—Waxy thick layer outside epidermis, prevents the loss of water.
 (b) Epidermis : Outer most layer of primary plant body.
 (c) Epidermal hair : help in absorbing water and mineral from soil.
 (d) Trichomes : help in preventing water loss due to transpiration.
 (e) Stomata : Regulate process of transpiration and gaseous exchange.
 Stomatal apparatus : The stomatal aperture, guard cells and surrounding 
subsidiary cells are together called stomatal apparatus.
2. The ground tissue system : It is made up of parenchyma, collenchyma,
sclerenchyma. In dicot stems and roots (both monocots and dicots) the ground
tissue is divided into hypodermis, cortex, endodermis, pericycle, medullary
rays and pith.
3. The vascular tissue system : It includes vascular bundles which are made
up of xylem and phloem.
Nucleus
Page 5


Points to Remember
Anatomy : Anatomy is the study of internal structure of organisms. Plant 
anatomy includes organisation and structure of tissues.
Tissue is a group is cells having a common origin and usually performing 
a common function.
There are two types of tissues (i) Meristematic (ii) Permanent
Meristematic tissues : The meristematic tissue is made up of the cells which 
have the capability to divide. Meristems in plants are restricted to a specialised 
regions and responsible to the growth of plants.
Meristems
      Apical meristem  Intercalary meristem        Lateral Meristem
? Occurs at  the tips of ? Occurs between ? Occurs in the mature
roots and shoots mature tissue region of roots and
shoots
? Primary meristem ? Primary meristem ? Secondary meristem
? Increase the length of ? Occur in grasses and ? Appears later than
plant regenerate parts primary meristem
removed by grazers and responsible for
secondary growth
 Axillary bud : The buds which are present in the axils of leaves (Consist  
of cells left behind from shoot apical meristem) and are responsible for forming 
branches of flowers.
Permanent tissues : The permanent tissues are derived from meristematic 
tissue, are composed of cells, which have lost the ability to divide and have become 
structurally and functionally specialised.
Types of Permanent Tissue
Simple (i) Complex (ii)
    Parenchyma        Collenchyma Scierenchyma        Xylem    Phloem
Parenchyma : Living, thin walled isodiametric cells, with interceullar spaces, 
cell wall is made up of cellulose. It performs the functions like photosynthesis, 
storage, secretion.
Collenchyma : It is formed of living, closely packed cells. Its cells are 
thicknened at the corners due to depositon of celluose and pectin. It provide 
mechanical support to the growing parts of the plant. It is either found in 
homogenous layer or patches.
Sclerenchyma : It is formed of dead cells with thick and lignified walls. 
Provide mechanical support to organs. They have two types of cells : fibres and 
sclereids.
(a) Fibers—are thick walled,elongated and pointed cells.
(b) Sclereids—are spherical, oval or cylindrical, highly thickened dead cells 
with narrow lumen. Found in walls of nut, pulp of fruits like guava, seed coat of 
legumes and leaves of tea.
Xylem : Xylem consists of tracheids vessels, xylem fibres and xylem 
parenchyma. It conducts water and minerals from roots to other parts of plant.
(a) Tracheids—Tube like cells with thick and lignified walls and tapering 
ends; dead, without protoplasm.
(b) Vessel—long cylindrical structure made up of many cells with large 
central cavity, devoid of protoplasm. Present in angiosperms.
(c) Xylem fibres —highly thickened walls; with obliterated lumens; septate 
or aseptate.
(d) Xylem parenchyma—living and thin walled; cell walls made up 
cellulose, store food material in form of starch or fat.
Radial conduction of water takes place by ray parenchymatous cells
Protoxylem : The first formed primary xylem elements.
Metaxylem : The later formed primary xylem.
Endarch : Protoxylem lies towards the centre and metaxylem towards the 
periphery of the organ; in stem
Exarch : Protoxylem toward periphery and metaxylem towards centre; in 
roots.
Phloem :Phloem consists of sieve tube elements, companion cells, phloem 
fibres and phloem parenchyma; Phloem transports the food material from leaves 
to various parts of the plant.
(a) Sieve tube elements :
? long tube like structures arranged longitudinally.
? associated with companion cells.
? end walls are perforated to form sieve plates.
? functions of sieve tubes are controlled by the nucleus of companion cells.
(b) Companion cells
? Specialised parenchymatous cells associated with sieve tube elements
? Connected with sieve tube elements by pit fields present between their
common longitudinal walls
? Help to maintain pressure gradient in sieve tubes.
(c)  Phloem Parenchyma
? made up of elongated, tapering cylindrical cells with dense cytoplasm and
nucleus.
? cell wall made of cellulose with pits through which plasmodesmatal
connections exist between cells.
? store food material.
(d)  Phloem fibers (bast fibers)
? are sclerenchymatous; absent in primary phloem but present in secondary
phloem.
? elongated, unbranched pointed, needle like apices with thick cell walls.
 Protophloem : First formed phloem with narrow sieve tubes.
  Metaphloem : Later formed phloem with bigger sieve tubes.
The Tissue System :
1. Epidermal tissue system : It includes cuticle, epidermis, epidermal hairs,
root hairs, trichomes and stomata.
The Tissue System :
(1) Epdiermal tissue system : It includes.
(a) Cuticle—Waxy thick layer outside epidermis, prevents the loss of water.
 (b) Epidermis : Outer most layer of primary plant body.
 (c) Epidermal hair : help in absorbing water and mineral from soil.
 (d) Trichomes : help in preventing water loss due to transpiration.
 (e) Stomata : Regulate process of transpiration and gaseous exchange.
 Stomatal apparatus : The stomatal aperture, guard cells and surrounding 
subsidiary cells are together called stomatal apparatus.
2. The ground tissue system : It is made up of parenchyma, collenchyma,
sclerenchyma. In dicot stems and roots (both monocots and dicots) the ground
tissue is divided into hypodermis, cortex, endodermis, pericycle, medullary
rays and pith.
3. The vascular tissue system : It includes vascular bundles which are made
up of xylem and phloem.
Nucleus
65
Anatomy of Root
               Dicot Root Monocot Root
1. Cotext is comparatively narrow. 1. Cortex is very wide.
2. Endodermis is less thicknened 2. Endodermal cells are highly
casparian strips are more thickened  Casparian strips are visible 
prominent. only in young roots.
3. The xylem and phloem bundles 3. Xylem and phloem are more than 6
varies from 2 to 5. (polyarch).
4. Pith is absent or very small. 4. Well developed pith is present.
5. Secondary growth takes place 5. Secondary growth is absent.
with the help of vascular cambium
and cork cambium.
Casparian Strips—The tangential as well as radial walls of endodermal
cells of dicot roots have deposition of water impermeable, waxy material, suberin 
in the form of casparian strips.
Antomy of Stem
             Dicot Stem            Monocot Stem
1. The ground tissue is differentiated 1. The ground tissue is made up of similar
into cortex, endodermis,pericycle  cells.
and pitch
2. The vascular bundles are arranged 2. The vascular bundles are scattered
in a ring.  throughout the ground tissue.
3. Vascular bundles are open, without 3. Vascular bundles are closed,
surrounded 
 bundle sheath and wedge-shaped  by sclerenchymatous bundle sheath,
 outline.  oval or rounded in shape.
4. The stem shows secondary growth 4. Secondary growth is absent.
due to presence of cambium
between xylem and phloem.
Secondary growth dicot stem—An increase in the girth (diameter) in 
plants. Vascular cambium and cork cambium (laternal meristems) are involved 
in secondary growth.