Allen Biology : Unit 1 (Diversity In Living World) Notes | EduRev

MBBS : Allen Biology : Unit 1 (Diversity In Living World) Notes | EduRev

 Page 1


Session 2019-20
ALLEN
S.No.                CONTENTS Page
1. T axonomy 1
2. History of T axonomy 10
3. Kingdom Monera 14
4. Kingdom Protista 32
5. Kingdom Fungi 37
6. Plant Kingdom 53
A. Algae 53
B. Bryophyta 62
C. Pteridophyta 66
D. Gymnosperms 71
7. Exercise-I (Conceptual Questions) 83
8. Exercise-II (Previous Y ears Questions) 100
9. Exercise-III (Analytical Questions) 118
10. Exercise-IV (Assertion & Reason) 128
11. Virus 132
12. Lichen 135
13. Mycorrhiza 137
14. The living World 138
DIVERSITY IN THE LIVING WORLD
E
NEET SYLLABUS
DIVERSITY IN LIVING WORLD : What is living? ; Biodiversity; Need for classification; Three domains of life;
Taxonomy & Systematics; Concept of species and taxonomical hierarchy; Binomial nomenclature; Tools for study
of Taxonomy ? Museums, Zoos, Herbaria, Botanical gardens.  Five kingdom classification; salient features and
classification of Monera; Protista and Fungi into major groups; Lichens; Viruses and Viroids. Salient features and
classification of plants into major groups-Algae, Bryophytes, Pteridophytes, Gymnosperms and Angiosperms (three
to five salient and distinguishing features and at least two examples of each category); Angiosperms- classification
up to class, characteristic features and examples).
Page 2


Session 2019-20
ALLEN
S.No.                CONTENTS Page
1. T axonomy 1
2. History of T axonomy 10
3. Kingdom Monera 14
4. Kingdom Protista 32
5. Kingdom Fungi 37
6. Plant Kingdom 53
A. Algae 53
B. Bryophyta 62
C. Pteridophyta 66
D. Gymnosperms 71
7. Exercise-I (Conceptual Questions) 83
8. Exercise-II (Previous Y ears Questions) 100
9. Exercise-III (Analytical Questions) 118
10. Exercise-IV (Assertion & Reason) 128
11. Virus 132
12. Lichen 135
13. Mycorrhiza 137
14. The living World 138
DIVERSITY IN THE LIVING WORLD
E
NEET SYLLABUS
DIVERSITY IN LIVING WORLD : What is living? ; Biodiversity; Need for classification; Three domains of life;
Taxonomy & Systematics; Concept of species and taxonomical hierarchy; Binomial nomenclature; Tools for study
of Taxonomy ? Museums, Zoos, Herbaria, Botanical gardens.  Five kingdom classification; salient features and
classification of Monera; Protista and Fungi into major groups; Lichens; Viruses and Viroids. Salient features and
classification of plants into major groups-Algae, Bryophytes, Pteridophytes, Gymnosperms and Angiosperms (three
to five salient and distinguishing features and at least two examples of each category); Angiosperms- classification
up to class, characteristic features and examples).
Session 2019-20
ALLEN
Aristotle (384-322 BC)
He was a Greek philosopher and scientist born in the city of Stagira, Chalkidice
of classical Greece. His father died when Aristotle was a child. At eighteen, he joined
Plato's Academy in Athens and remained there until the age of thirty seven (c.347
BC). His writings cover many subjects including physics, biology, zoology,
metaphysics, poetry, politics and government. Shortly after Plato died,
Aristotle left Athens and, at the request of Philip of Macedon, tutored Alexander
the Great. Aristotle was the first genuine scientist in history and every scientist
is in his debt.He is regarded as father of biology and zoology. He first classified
plants into three groups (i) Herbs (ii) Shrubs (iii) Trees
Theophrastus (371-287 BC)
He was a Greek native of Eresos in Lesbos, was the successor to Aristotle. He
came to Athens at a young age and initially studied in Plato's school. After Plato's
death, he attached himself to Aristotle. He is often considered the "Father of
botany" for his works on plants.
The interests of Theophrastus were wide ranging, extending from biology and physics
to ethics and metaphysics. His two surviving botanical works, Enquiry into plants,
(Historia Plantarum) and On the causes of Plants, were an important influence on
Renaissance science. He classified plants into herbs, undershrubs, shrubs and trees.
He also gave the names annual, biennials and perennails to plants.
Theophrastus is also known as "Father of ancient plant taxonomy"
Carolus Linnaeus (23 May 1707 - 10 January 1778)
He was also known as Carl Von Linne he was a Swedish botanist, physician and
zoologist, who formalised the modern system of naming organisms called binomial
nomenclature. He is known by the epithet "Father of modern taxonomy". Many
his writings were in Latin, and his name is rendered in Latin as Carolus Linnaeus
(abbreviation - "Linn").
Linnaeus received most of his higher education at Uppsala University, and began
giving lectures in botany there in 1730. He published a first edition of his Systema
Naturae in the Netherlands. He then returned to Sweden, where he became
professor of medicine and botany at Uppsala university.
Ernst Mayr (1904-2004)
Born on 5 July 1904, in Kempten, Germany, ERNST MAYR, the Harvard
University evolutionary biologist who has been called ?The Darwin of the 20th
century?, was one of the 100 greatest scientists of all time. Mayr joined Harvard?s
Faculty of Arts and Sciences in 1953 and retired in 1975, assuming the title
Alexander Agassiz Professor of Zoology Emeritus. Throughout his nearly
80-year career , his research spanned ornithology, taxonomy, zoogeography,
evolution, systematics, and the history and philosophy of biology. He almost
single-handedly made the origin of species diversity the central question of
evolutionary biology that it is today. He also pioneered the currently accepted
definition of a biological species. Mayr was awarded the three prizes widely
regarded as the triple crown of biology: the Balzan Prize in 1983, the
International Prize for Biology in 1994, and the Crafoord Prize in 1999.
Mayr died at the age of 100 in the year 2004.
Page 3


Session 2019-20
ALLEN
S.No.                CONTENTS Page
1. T axonomy 1
2. History of T axonomy 10
3. Kingdom Monera 14
4. Kingdom Protista 32
5. Kingdom Fungi 37
6. Plant Kingdom 53
A. Algae 53
B. Bryophyta 62
C. Pteridophyta 66
D. Gymnosperms 71
7. Exercise-I (Conceptual Questions) 83
8. Exercise-II (Previous Y ears Questions) 100
9. Exercise-III (Analytical Questions) 118
10. Exercise-IV (Assertion & Reason) 128
11. Virus 132
12. Lichen 135
13. Mycorrhiza 137
14. The living World 138
DIVERSITY IN THE LIVING WORLD
E
NEET SYLLABUS
DIVERSITY IN LIVING WORLD : What is living? ; Biodiversity; Need for classification; Three domains of life;
Taxonomy & Systematics; Concept of species and taxonomical hierarchy; Binomial nomenclature; Tools for study
of Taxonomy ? Museums, Zoos, Herbaria, Botanical gardens.  Five kingdom classification; salient features and
classification of Monera; Protista and Fungi into major groups; Lichens; Viruses and Viroids. Salient features and
classification of plants into major groups-Algae, Bryophytes, Pteridophytes, Gymnosperms and Angiosperms (three
to five salient and distinguishing features and at least two examples of each category); Angiosperms- classification
up to class, characteristic features and examples).
Session 2019-20
ALLEN
Aristotle (384-322 BC)
He was a Greek philosopher and scientist born in the city of Stagira, Chalkidice
of classical Greece. His father died when Aristotle was a child. At eighteen, he joined
Plato's Academy in Athens and remained there until the age of thirty seven (c.347
BC). His writings cover many subjects including physics, biology, zoology,
metaphysics, poetry, politics and government. Shortly after Plato died,
Aristotle left Athens and, at the request of Philip of Macedon, tutored Alexander
the Great. Aristotle was the first genuine scientist in history and every scientist
is in his debt.He is regarded as father of biology and zoology. He first classified
plants into three groups (i) Herbs (ii) Shrubs (iii) Trees
Theophrastus (371-287 BC)
He was a Greek native of Eresos in Lesbos, was the successor to Aristotle. He
came to Athens at a young age and initially studied in Plato's school. After Plato's
death, he attached himself to Aristotle. He is often considered the "Father of
botany" for his works on plants.
The interests of Theophrastus were wide ranging, extending from biology and physics
to ethics and metaphysics. His two surviving botanical works, Enquiry into plants,
(Historia Plantarum) and On the causes of Plants, were an important influence on
Renaissance science. He classified plants into herbs, undershrubs, shrubs and trees.
He also gave the names annual, biennials and perennails to plants.
Theophrastus is also known as "Father of ancient plant taxonomy"
Carolus Linnaeus (23 May 1707 - 10 January 1778)
He was also known as Carl Von Linne he was a Swedish botanist, physician and
zoologist, who formalised the modern system of naming organisms called binomial
nomenclature. He is known by the epithet "Father of modern taxonomy". Many
his writings were in Latin, and his name is rendered in Latin as Carolus Linnaeus
(abbreviation - "Linn").
Linnaeus received most of his higher education at Uppsala University, and began
giving lectures in botany there in 1730. He published a first edition of his Systema
Naturae in the Netherlands. He then returned to Sweden, where he became
professor of medicine and botany at Uppsala university.
Ernst Mayr (1904-2004)
Born on 5 July 1904, in Kempten, Germany, ERNST MAYR, the Harvard
University evolutionary biologist who has been called ?The Darwin of the 20th
century?, was one of the 100 greatest scientists of all time. Mayr joined Harvard?s
Faculty of Arts and Sciences in 1953 and retired in 1975, assuming the title
Alexander Agassiz Professor of Zoology Emeritus. Throughout his nearly
80-year career , his research spanned ornithology, taxonomy, zoogeography,
evolution, systematics, and the history and philosophy of biology. He almost
single-handedly made the origin of species diversity the central question of
evolutionary biology that it is today. He also pioneered the currently accepted
definition of a biological species. Mayr was awarded the three prizes widely
regarded as the triple crown of biology: the Balzan Prize in 1983, the
International Prize for Biology in 1994, and the Crafoord Prize in 1999.
Mayr died at the age of 100 in the year 2004.
Session 2019-20
ALLEN
Z:\NODE02\B0AI-B0\TARGET\BIO\ENG\MODULE_4\01-PLANT DIVERSITY\01-PLANT.P65
1 E
Pre-Medical : Biology
ALLE N
PLANT DIVERSITY
Taxonomy : Taxis = arrangement, nomos = law
This word was proposed by A.P. de. Candolle in his book "Theories elementaire de la botanique"
(Theory of elementary botany)
Taxonomy includes study of following points
(1) Identification : A process by which an organism is recognised from the other already known organisms
and is assigned to a particular taxonomic group is called identification.
(2) Nomenclature : Naming of organisms according to international scientific rules is called nomenclature.
(3) Classification : A process by which any organism is grouped into convenient categories on the basis of
some easily observable characters.
Systematics :-
The term systematics was given by Linnaeus. The word systematics derived from Latin word "Systema" which
means "systematic arrangment of organisms". Linnaeus used "Systema Naturae" as a title of his publication.
Systematics includes identification, nomenclature, classification and evolutionary relationship between organisms.
Note :- In modern taxonomical studies, taxonomists use external and internal structure, along with the structure
of cell, development process and ecological information of organisms.
TYPES OF TAXONOMY
1. Cytotaxonomy : The use of cytological characters of plants in classification or in solving taxonomic problems
is called cytotaxonomy. Cytotaxonomy is based on cytological information like chromosome number, structure
and behaviour etc.
2. Chemotaxonomy : It is based on the chemical constituents of plants.
The basic chemical compounds used in chemotaxonomy are alkaloids, carotenoids, tannins,  polysaccharide,
nucleic acids, fatty acids, amino acids, aromatic compounds etc.
Some Informations :
l Practical significance of taxonomy is ® Identification of unknown organism.
l Maximum diversity is found in tropical rain forests.
l Second maximum diversity is found in coral reefs
l The number of species that are known and described range betwen 1.7 ? 1.8 million. This refers to
 biodiversity or the number and types of organism present on earth.
Page 4


Session 2019-20
ALLEN
S.No.                CONTENTS Page
1. T axonomy 1
2. History of T axonomy 10
3. Kingdom Monera 14
4. Kingdom Protista 32
5. Kingdom Fungi 37
6. Plant Kingdom 53
A. Algae 53
B. Bryophyta 62
C. Pteridophyta 66
D. Gymnosperms 71
7. Exercise-I (Conceptual Questions) 83
8. Exercise-II (Previous Y ears Questions) 100
9. Exercise-III (Analytical Questions) 118
10. Exercise-IV (Assertion & Reason) 128
11. Virus 132
12. Lichen 135
13. Mycorrhiza 137
14. The living World 138
DIVERSITY IN THE LIVING WORLD
E
NEET SYLLABUS
DIVERSITY IN LIVING WORLD : What is living? ; Biodiversity; Need for classification; Three domains of life;
Taxonomy & Systematics; Concept of species and taxonomical hierarchy; Binomial nomenclature; Tools for study
of Taxonomy ? Museums, Zoos, Herbaria, Botanical gardens.  Five kingdom classification; salient features and
classification of Monera; Protista and Fungi into major groups; Lichens; Viruses and Viroids. Salient features and
classification of plants into major groups-Algae, Bryophytes, Pteridophytes, Gymnosperms and Angiosperms (three
to five salient and distinguishing features and at least two examples of each category); Angiosperms- classification
up to class, characteristic features and examples).
Session 2019-20
ALLEN
Aristotle (384-322 BC)
He was a Greek philosopher and scientist born in the city of Stagira, Chalkidice
of classical Greece. His father died when Aristotle was a child. At eighteen, he joined
Plato's Academy in Athens and remained there until the age of thirty seven (c.347
BC). His writings cover many subjects including physics, biology, zoology,
metaphysics, poetry, politics and government. Shortly after Plato died,
Aristotle left Athens and, at the request of Philip of Macedon, tutored Alexander
the Great. Aristotle was the first genuine scientist in history and every scientist
is in his debt.He is regarded as father of biology and zoology. He first classified
plants into three groups (i) Herbs (ii) Shrubs (iii) Trees
Theophrastus (371-287 BC)
He was a Greek native of Eresos in Lesbos, was the successor to Aristotle. He
came to Athens at a young age and initially studied in Plato's school. After Plato's
death, he attached himself to Aristotle. He is often considered the "Father of
botany" for his works on plants.
The interests of Theophrastus were wide ranging, extending from biology and physics
to ethics and metaphysics. His two surviving botanical works, Enquiry into plants,
(Historia Plantarum) and On the causes of Plants, were an important influence on
Renaissance science. He classified plants into herbs, undershrubs, shrubs and trees.
He also gave the names annual, biennials and perennails to plants.
Theophrastus is also known as "Father of ancient plant taxonomy"
Carolus Linnaeus (23 May 1707 - 10 January 1778)
He was also known as Carl Von Linne he was a Swedish botanist, physician and
zoologist, who formalised the modern system of naming organisms called binomial
nomenclature. He is known by the epithet "Father of modern taxonomy". Many
his writings were in Latin, and his name is rendered in Latin as Carolus Linnaeus
(abbreviation - "Linn").
Linnaeus received most of his higher education at Uppsala University, and began
giving lectures in botany there in 1730. He published a first edition of his Systema
Naturae in the Netherlands. He then returned to Sweden, where he became
professor of medicine and botany at Uppsala university.
Ernst Mayr (1904-2004)
Born on 5 July 1904, in Kempten, Germany, ERNST MAYR, the Harvard
University evolutionary biologist who has been called ?The Darwin of the 20th
century?, was one of the 100 greatest scientists of all time. Mayr joined Harvard?s
Faculty of Arts and Sciences in 1953 and retired in 1975, assuming the title
Alexander Agassiz Professor of Zoology Emeritus. Throughout his nearly
80-year career , his research spanned ornithology, taxonomy, zoogeography,
evolution, systematics, and the history and philosophy of biology. He almost
single-handedly made the origin of species diversity the central question of
evolutionary biology that it is today. He also pioneered the currently accepted
definition of a biological species. Mayr was awarded the three prizes widely
regarded as the triple crown of biology: the Balzan Prize in 1983, the
International Prize for Biology in 1994, and the Crafoord Prize in 1999.
Mayr died at the age of 100 in the year 2004.
Session 2019-20
ALLEN
Z:\NODE02\B0AI-B0\TARGET\BIO\ENG\MODULE_4\01-PLANT DIVERSITY\01-PLANT.P65
1 E
Pre-Medical : Biology
ALLE N
PLANT DIVERSITY
Taxonomy : Taxis = arrangement, nomos = law
This word was proposed by A.P. de. Candolle in his book "Theories elementaire de la botanique"
(Theory of elementary botany)
Taxonomy includes study of following points
(1) Identification : A process by which an organism is recognised from the other already known organisms
and is assigned to a particular taxonomic group is called identification.
(2) Nomenclature : Naming of organisms according to international scientific rules is called nomenclature.
(3) Classification : A process by which any organism is grouped into convenient categories on the basis of
some easily observable characters.
Systematics :-
The term systematics was given by Linnaeus. The word systematics derived from Latin word "Systema" which
means "systematic arrangment of organisms". Linnaeus used "Systema Naturae" as a title of his publication.
Systematics includes identification, nomenclature, classification and evolutionary relationship between organisms.
Note :- In modern taxonomical studies, taxonomists use external and internal structure, along with the structure
of cell, development process and ecological information of organisms.
TYPES OF TAXONOMY
1. Cytotaxonomy : The use of cytological characters of plants in classification or in solving taxonomic problems
is called cytotaxonomy. Cytotaxonomy is based on cytological information like chromosome number, structure
and behaviour etc.
2. Chemotaxonomy : It is based on the chemical constituents of plants.
The basic chemical compounds used in chemotaxonomy are alkaloids, carotenoids, tannins,  polysaccharide,
nucleic acids, fatty acids, amino acids, aromatic compounds etc.
Some Informations :
l Practical significance of taxonomy is ® Identification of unknown organism.
l Maximum diversity is found in tropical rain forests.
l Second maximum diversity is found in coral reefs
l The number of species that are known and described range betwen 1.7 ? 1.8 million. This refers to
 biodiversity or the number and types of organism present on earth.
Session 2019-20
ALLEN
Z:\NODE02\B0AI-B0\TARGET\BIO\ENG\MODULE_4\01-PLANT DIVERSITY\01-PLANT.P65
2 E
Pre-Medical : Biology
ALLE N
NOMENCLATURE
Binomial system :
Given by Carolus Linnaeus
Carolus Linnaeus :- Linnaeus used this nomenclature system for the first time on large scale and proposed
scientific name of many plants and animals.
l Linnaeus is the founder of binomial system.
l Linnaeus proposed scientific name of plants in his book "Species plantarum". It was published on
1 May 1753. So this was the initiation of binomial system for plants.So any name proposed (for plants) before
this date is not accepted today.
l Linnaeus proposed scientific name of animals in his book "Systema naturae" (10
th
 edition).
l This 10
th
 edition of Systema naturae was  published on 1 August 1758. So initiation of binomial system
for animals is believed to be started on 1 Aug, 1758.
ICBN
"International Code of Botanical Nomenclature"
l Collection of rules regarding scientific nomenclature of plants is known as ICBN.
l ICBN was first accepted in 1961.
Main rules of ICBN :-
(1) According to binomial system name of any species consists of two components or words -
(i) Generic name - Name of genus
(ii) Specific epithet
e.g. Solanum tuberosum (Potato) Mangifera  indica (Mango)
¯ ¯ ¯      ¯
Generic name  Specific epithet Generic name  Specific epithet
(2) In plant nomenclature (ICBN) tautonyms are not valid i.e. generic name and specific epithet should not be same
in plants.
eg. Mangifera mangifera
But tautonyms are valid in animal nomenclature (ICZN-International Code of Zoological Nomenclature)
eg. Naja naja (Indian cobra) ,  Rattus rattus (Rat)
(3) First letter of generic name should be in capital letter and first letter of specific epithet should be in small letter.
eg. Mangifera indica
(4) When written with free hand or typed, then generic name and specific epithet should be separately underlined.
But during printing name should be in italics to indicate their Latin origin.
(5) Name of scientist (who proposed nomenclature) should be written in short after the specific epithet
eg. Mangifera indica Linn.
(6) Name of scientist should be neither underlined nor in italics, but written in Roman letters (simple alphabets)
(7) Scientific names should be derived from Latin (usually) or Greek languages because they are dead languages.
(8) Type specimen (Herbarium Sheet) of newly discovered plant should be placed in herbarium.
Page 5


Session 2019-20
ALLEN
S.No.                CONTENTS Page
1. T axonomy 1
2. History of T axonomy 10
3. Kingdom Monera 14
4. Kingdom Protista 32
5. Kingdom Fungi 37
6. Plant Kingdom 53
A. Algae 53
B. Bryophyta 62
C. Pteridophyta 66
D. Gymnosperms 71
7. Exercise-I (Conceptual Questions) 83
8. Exercise-II (Previous Y ears Questions) 100
9. Exercise-III (Analytical Questions) 118
10. Exercise-IV (Assertion & Reason) 128
11. Virus 132
12. Lichen 135
13. Mycorrhiza 137
14. The living World 138
DIVERSITY IN THE LIVING WORLD
E
NEET SYLLABUS
DIVERSITY IN LIVING WORLD : What is living? ; Biodiversity; Need for classification; Three domains of life;
Taxonomy & Systematics; Concept of species and taxonomical hierarchy; Binomial nomenclature; Tools for study
of Taxonomy ? Museums, Zoos, Herbaria, Botanical gardens.  Five kingdom classification; salient features and
classification of Monera; Protista and Fungi into major groups; Lichens; Viruses and Viroids. Salient features and
classification of plants into major groups-Algae, Bryophytes, Pteridophytes, Gymnosperms and Angiosperms (three
to five salient and distinguishing features and at least two examples of each category); Angiosperms- classification
up to class, characteristic features and examples).
Session 2019-20
ALLEN
Aristotle (384-322 BC)
He was a Greek philosopher and scientist born in the city of Stagira, Chalkidice
of classical Greece. His father died when Aristotle was a child. At eighteen, he joined
Plato's Academy in Athens and remained there until the age of thirty seven (c.347
BC). His writings cover many subjects including physics, biology, zoology,
metaphysics, poetry, politics and government. Shortly after Plato died,
Aristotle left Athens and, at the request of Philip of Macedon, tutored Alexander
the Great. Aristotle was the first genuine scientist in history and every scientist
is in his debt.He is regarded as father of biology and zoology. He first classified
plants into three groups (i) Herbs (ii) Shrubs (iii) Trees
Theophrastus (371-287 BC)
He was a Greek native of Eresos in Lesbos, was the successor to Aristotle. He
came to Athens at a young age and initially studied in Plato's school. After Plato's
death, he attached himself to Aristotle. He is often considered the "Father of
botany" for his works on plants.
The interests of Theophrastus were wide ranging, extending from biology and physics
to ethics and metaphysics. His two surviving botanical works, Enquiry into plants,
(Historia Plantarum) and On the causes of Plants, were an important influence on
Renaissance science. He classified plants into herbs, undershrubs, shrubs and trees.
He also gave the names annual, biennials and perennails to plants.
Theophrastus is also known as "Father of ancient plant taxonomy"
Carolus Linnaeus (23 May 1707 - 10 January 1778)
He was also known as Carl Von Linne he was a Swedish botanist, physician and
zoologist, who formalised the modern system of naming organisms called binomial
nomenclature. He is known by the epithet "Father of modern taxonomy". Many
his writings were in Latin, and his name is rendered in Latin as Carolus Linnaeus
(abbreviation - "Linn").
Linnaeus received most of his higher education at Uppsala University, and began
giving lectures in botany there in 1730. He published a first edition of his Systema
Naturae in the Netherlands. He then returned to Sweden, where he became
professor of medicine and botany at Uppsala university.
Ernst Mayr (1904-2004)
Born on 5 July 1904, in Kempten, Germany, ERNST MAYR, the Harvard
University evolutionary biologist who has been called ?The Darwin of the 20th
century?, was one of the 100 greatest scientists of all time. Mayr joined Harvard?s
Faculty of Arts and Sciences in 1953 and retired in 1975, assuming the title
Alexander Agassiz Professor of Zoology Emeritus. Throughout his nearly
80-year career , his research spanned ornithology, taxonomy, zoogeography,
evolution, systematics, and the history and philosophy of biology. He almost
single-handedly made the origin of species diversity the central question of
evolutionary biology that it is today. He also pioneered the currently accepted
definition of a biological species. Mayr was awarded the three prizes widely
regarded as the triple crown of biology: the Balzan Prize in 1983, the
International Prize for Biology in 1994, and the Crafoord Prize in 1999.
Mayr died at the age of 100 in the year 2004.
Session 2019-20
ALLEN
Z:\NODE02\B0AI-B0\TARGET\BIO\ENG\MODULE_4\01-PLANT DIVERSITY\01-PLANT.P65
1 E
Pre-Medical : Biology
ALLE N
PLANT DIVERSITY
Taxonomy : Taxis = arrangement, nomos = law
This word was proposed by A.P. de. Candolle in his book "Theories elementaire de la botanique"
(Theory of elementary botany)
Taxonomy includes study of following points
(1) Identification : A process by which an organism is recognised from the other already known organisms
and is assigned to a particular taxonomic group is called identification.
(2) Nomenclature : Naming of organisms according to international scientific rules is called nomenclature.
(3) Classification : A process by which any organism is grouped into convenient categories on the basis of
some easily observable characters.
Systematics :-
The term systematics was given by Linnaeus. The word systematics derived from Latin word "Systema" which
means "systematic arrangment of organisms". Linnaeus used "Systema Naturae" as a title of his publication.
Systematics includes identification, nomenclature, classification and evolutionary relationship between organisms.
Note :- In modern taxonomical studies, taxonomists use external and internal structure, along with the structure
of cell, development process and ecological information of organisms.
TYPES OF TAXONOMY
1. Cytotaxonomy : The use of cytological characters of plants in classification or in solving taxonomic problems
is called cytotaxonomy. Cytotaxonomy is based on cytological information like chromosome number, structure
and behaviour etc.
2. Chemotaxonomy : It is based on the chemical constituents of plants.
The basic chemical compounds used in chemotaxonomy are alkaloids, carotenoids, tannins,  polysaccharide,
nucleic acids, fatty acids, amino acids, aromatic compounds etc.
Some Informations :
l Practical significance of taxonomy is ® Identification of unknown organism.
l Maximum diversity is found in tropical rain forests.
l Second maximum diversity is found in coral reefs
l The number of species that are known and described range betwen 1.7 ? 1.8 million. This refers to
 biodiversity or the number and types of organism present on earth.
Session 2019-20
ALLEN
Z:\NODE02\B0AI-B0\TARGET\BIO\ENG\MODULE_4\01-PLANT DIVERSITY\01-PLANT.P65
2 E
Pre-Medical : Biology
ALLE N
NOMENCLATURE
Binomial system :
Given by Carolus Linnaeus
Carolus Linnaeus :- Linnaeus used this nomenclature system for the first time on large scale and proposed
scientific name of many plants and animals.
l Linnaeus is the founder of binomial system.
l Linnaeus proposed scientific name of plants in his book "Species plantarum". It was published on
1 May 1753. So this was the initiation of binomial system for plants.So any name proposed (for plants) before
this date is not accepted today.
l Linnaeus proposed scientific name of animals in his book "Systema naturae" (10
th
 edition).
l This 10
th
 edition of Systema naturae was  published on 1 August 1758. So initiation of binomial system
for animals is believed to be started on 1 Aug, 1758.
ICBN
"International Code of Botanical Nomenclature"
l Collection of rules regarding scientific nomenclature of plants is known as ICBN.
l ICBN was first accepted in 1961.
Main rules of ICBN :-
(1) According to binomial system name of any species consists of two components or words -
(i) Generic name - Name of genus
(ii) Specific epithet
e.g. Solanum tuberosum (Potato) Mangifera  indica (Mango)
¯ ¯ ¯      ¯
Generic name  Specific epithet Generic name  Specific epithet
(2) In plant nomenclature (ICBN) tautonyms are not valid i.e. generic name and specific epithet should not be same
in plants.
eg. Mangifera mangifera
But tautonyms are valid in animal nomenclature (ICZN-International Code of Zoological Nomenclature)
eg. Naja naja (Indian cobra) ,  Rattus rattus (Rat)
(3) First letter of generic name should be in capital letter and first letter of specific epithet should be in small letter.
eg. Mangifera indica
(4) When written with free hand or typed, then generic name and specific epithet should be separately underlined.
But during printing name should be in italics to indicate their Latin origin.
(5) Name of scientist (who proposed nomenclature) should be written in short after the specific epithet
eg. Mangifera indica Linn.
(6) Name of scientist should be neither underlined nor in italics, but written in Roman letters (simple alphabets)
(7) Scientific names should be derived from Latin (usually) or Greek languages because they are dead languages.
(8) Type specimen (Herbarium Sheet) of newly discovered plant should be placed in herbarium.
Session 2019-20
ALLEN
Z:\NODE02\B0AI-B0\TARGET\BIO\ENG\MODULE_4\01-PLANT DIVERSITY\01-PLANT.P65
3 E
Pre-Medical : Biology
ALLE N
Trinomial system :-
 According to this system name of any organism is composed of three words -
(i) Generic name (ii) Specific epithet (iii) Subspecific epithet (Name of variety)
eg. Brassica oleracea botrytis (Cauliflower)
Brassica oleracea capitata (Cabbage)
Brassica oleracea caulorapa (Knol-Khol)
     ¯      ¯     ¯
Generic Specific Variety
name epithet
CLASSIFICATION
Biological classification :?
The art of identifying distinctions among organisms and placing them  into groups that reflect their most
significant features and relationship is called biological classification.
The purpose of biological classification is to organise the vast number of known organisms into categories that
could be named, remembered and studied.
Type of Biological classification
(i) Practical classification :- In this type of classification, plants are classified on the basis of their economic
importance or human use. This classification system is the earliest system.
e.g. Oil yielding plants ® Coconut, Walnut, Soyabean
Fibre yielding plants ® Jute, Cotton
Medicinal plants ® Rauwolfia, Cinchona, Eucalyptus
Note : In this classification, any one plant can be a member of more than one group.
eg. Turmeric : Multi uses plant, it gives both medicines and spices.
(ii) Artificial classification :- In this type of classification plants are classified on the basis of one or two
morphological characters. i.e. over all morphology is not considered.
for e.g. - Classification proposed by Linnaeus is Artificial
Linnaeus classified plant kingdom on the basis stamen (mainly) into 24 classes.
Note :
(1) In the book "Genera Plantarum" Linnaeus classified the plant kingdom into 24 classes on the basis of
stamen so, classification of Linnaeus is also called sexual classification.
(2) Linnaeus divided phanerogams (gymnosperm and angiosperms) into 23 classes and he included other
plants such as algae, fungi, mosses (bryophytes) and ferns (pteridophytes) in a separate class called
cryptogamia.
(3) In this system equal weightage is given to both vegetative and reproductive characters.
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