Chapter 1 The Living World

1 THE LIVING WORLD

CHAPTER NO. 1 THE LIVING WORLD

BIOLOGY:

The branch of science which deals with the study of life forms and living processes.

WHAT IS LIVING ?

The characters which are common in all living beings are called basic characters of living organisms. Some of these characters are listed below:

i) AIl living organisms grow, reproduce and adapt to the environment.

ii) They use energy for metabolism.

iii) All living beings respond to the change in environment.

iv)AIl living beings have ability to evolve with time.

V) AIl living organism store energy in the form of ATP in their cells.

Vi) All living beings die after a definite life span.

vii) Cellular organization of the body is the defining feature of life forms.

viii) CONSCIOUSNESS ‘is the ability to sense their surrounding or environment and respond to these environmental stimuli. Thus consciousness is the defining property of living organisms.

Thus LIVING ORGANSIMS: can be defined as self replicating, evolving and self regulating interactive systems capable of responding to external stimuli. All living organisms present, past and future, are linked to one another by sharing of the common genetic material, but to varying degrees.

DIVERSITY IN THE LIVING WORLD:

BIO DIVERSITY:

Bio diversity includes all type of organisms present on the earth. Till now 1.7- 1.8 million species have been described. There are million types of plants and animals known in their own areas by local names.

EARNST MAYR was called “THE DARWIN OF 20™ CENTUARY”. He gave the currently accepted definition of biological species.

SYSTEMATICS:

The word systematic is derived from the Latin word ‘systema’ which means systematic arrangement of organisms. It is study of organisms and all their comparative and evolutionary relationship derived from comparative anatomy, comparative ecology, comparative physiology and comparative biochemistry.

The scope of systematic was later enlarged to include identification, nomenclature and classification.

LINNAEUS is considered as the FATHER OF SYSTEMATICS. The book “Systema Naturae” was written by CAROLUS LINNAEUS.

CLASSIFICATION:The branch of systematic which deals with ordering of organisms into groups on the basis of similarities and differences.

TAXONOMY:Based on characteristics, all living organisms can be classified into different taxa. This process of classification is called TAXONOMY. It is a branch of study that deals with principles and procedures of identification, nomenclature and classification of organisms. CAROLUS LINNAEUS is the FATHER OF TAXONOMY.

PART-A_:MULTIPLE CHOICE QUESTIONS:

1.Among the following choose the properties shown by the living organism exclusively-

(i) Growth

(ii) Increase in mass

(iii) Self-replication ability

(iv) Response to touch stimuli

(a) i and ii (b) i, ii and iii

2.Who is regarded as Father of Taxonomy?

(a) Hooker

(b) Linnaeus

(d) De Candolle

3. Diversity of organisms and their evolutionary relationship is studied scientifically under.

(a) Morphology

(b) Anatomy

(d) Systematics

4. Who is regarded as Father of Systematic?

(a) Hooker

(b) Linnaeus

(d) De Candolle

5.All living organism-

(a) Grow

(b) Reproduce

(d) All the above.

PART-B: TWO MARKS QUESTIONS

1. Define living organisms?

2. Define Systematics?

3. Define Taxonomy?

ANSWER KEY:- PART-A: MULTIPLE CHOICE QUESTIONS

1. c and d (Self-replication ability and Response to touch stimuli)

2. b (Linnaeus is regarded as Father of Taxonomy)

3. d (Systematics)

4. b (Linnaeus is regarded as Father of Systematic)

5. d (All living organism reproduce, grow and show metabolism.

NOMENCLATURE:As local names would vary from place to place, even within a country. Hence,there is a need to standardize the naming of living organisms such that aparticular organism is known by the same name all over the world. The processis called NOMENCLATURE.

IDENTIFICATION:Obviously, nomenclature or naming is only possible when the organisms is described correctly and we know to what organism the name is attached to.This is IDENTIFICATION.

SCIENTIFIC NAMES:In order to facilitate the study, number of scientists have established procedures to assign a scientific name to each known organism. This is acceptable to biologists all over the world .

BINOMIAL NOMENCLATURE:It was developed by CAROLUS LINNAEUS. All valid names for animals under binomial nomenclature are ones given by LINNAEUS IN TENTH EDITION OF HIS BOOK SYSTEMA NATURAE. All valid names for plants are the ones given by LINNAEUS IN HIS BOOK SPECIES PLANTARUM.

According to this system name of a species consist of TWO WORDS IN LATIN.The first word is GENERIC NAME OR GENUS and second name is the SPECIFIC NAME OR SPECIES. e.g. Mangifera indica (Mango), Homo sapiens (Man).

In certain cases the names of subspecies (Zoology) or variety (Botany) is also written after the two word name. It is TRINOMIAL NOMENCLATURE. e.g.

RULES OF BINOMIAL NOMENCLATURE:For plants, scientific names are based on agreed principles and criteria, which are provided in INTERNATIONAL CODE FOR_~ BOTANICAL NOMENCLATURE (ICBN) For animal taxonomists have evolved INTERNATIONAL CODE OF ZOOLOGICAL NOMENCLATURE (ICZN)

The names of bacteria and viruses are decided by INTERNATIONAL CODE OF

BACTERIOLOGICAL NOMENCLATURE (ICBN) and INTERNATIONAL CODE

OF VIRAL NOMENCLATURE (ICVN).

IMPORTANT RULES ARE:i)Each organism has a distinct scientific name having two words GENERIC AND SPECIFIC.

ii) The generic and specific words should not have less than three letters or more than twelve letters.

iii) The generic name is written first. Its first letter is always capital.

iv) The specific name is written after generic name. It starts with a small letter.

v) Biological names are generally in Latin and printed in italics. These areLatinized when used from other languages.

vi) Both the words in a biological name, when hand written, are separately underlined.

vii) The scientific name retains its original spellings.

viil) The same generic name can not be given in the same kingdom .The same specific word can be used several times but with different genera. e.g.Mangifera indica.

ix) Name of the author appear after the specific epithet i.e. at the end of biological name and is written in an abbreviated form e.g. Mangifera indica Linn. It is indicated that species was first described by Linnaeus.

x) When the name of the species is changed or revised, the name of the original discoverer is retained in brackets. Tne name of the new discoverer is written after the brackets e.g. Albizzia labbeck (Linn). Benth.

: ADVANTAGES OF BINOMIAL NOMENCLATURE

i) The names are universally recognized. They remain same in all languages.

ii) All the organisms known to science have been given scientific names irrespective of their size and importance.

iii) There is mechanism to provide scientific names to every newly discovered organism.

iv) Scientific names are often based on some characteristic of organism.

v) They indicate relationship with other species present in same genus.

vi)There is no change in spellings of a scientific name as the same has been obtained from dead Latin language.

vii) An inappropriate or incorrect name can be easily corrected.

LET US KNOW WHAT WE LEARN ?

1. VERY SHORT ANSWER TYPE QUESTIONS:

PART-A :- MULTIPLE CHOICE QUESTIONS

1. Who had written Systema Naturae?

(a) Ernst Mayr

(b) RH Whittaker

(d) WM Stanley

2. Who proposed Binomial system of Nomenclature?

(a) Candolle

(b) Bentham

(d) Hutchinson

3. Scientific name are printed (with English) and derived from

(a) Bold and English

(b) Italics and Latin

(d) Italics and French

4. Correctly written scientific name?

(a) Panthera Tigris

(b) Penthera Leo

(d) Apis INDICA

5. In which one of the following Carolos Linnaeus binomial nomenclature was first published?

(a) Systema Naturae

(b) Genera Animalium

(d) Species Plantarum

PART-B :- FILL IN THE BLANK :

1. Scientific name of man is .

2. The name of animals are decided by _ international code of

nomenclature.

3. The name of viruses are decided by international code of

nomenclature.

PART-C :- TRUE/ FALSE:

1. The generic name is written first. T/F

2. The specific name is written with a capital letter. T/F

3. The same generic name can be given twice in the same kingdom. T/F

2. SHORT ANSWER TYPE QUESTIONS:

1. Expand the term ICBN and ICZN

2. Why are living organism classified?

3. Discuss two advantages of binomial nomenclature.

3. LONG ANSWER TYPE QUESTION:

1. Discuss the important rules of binomial nomenclature.

ANSWER KEY -

PART-A :- MULTIPLE CHOICE QUESTIONS

1. c( Carolos Linnaeus)

2. c (Linnaeus)

3. b (Biological names are generally in Latin and printed in italics. These are Latinized when used from other languages. )

4. c (Mangifera indica)The generic name is written first. Its first Letter is always capital. The specific name is written after generic name. It starts with a small letter.

5. d (Species Plantarum) All valid names for plants are the ones given by LINNAEUS IN HIS BOOK SPECIES PLANTARUM.

PART-B:- FILL IN THE BLANK:

1. Homo sapiens. (The first word is GENERIC NAME OR GENUS and second

name is the SPECIFIC NAME OR SPECIES.)

2. Zoological. (For animal taxonomists have evolved INTERNATIONAL

CODE OF ZOOLOGICAL NOMENCLATURE (ICZN))

3. Viral. (INTERNATIONAL CODE OF VIRAL NOMENCLATURE (ICVN).)

PART-C:- TRUE/FALSE:

1. TRUE (Its first letter is always capital.)

2. FALSE (The specific name is written with small letters.)

3.FALSE (The same generic name cannot be given in the same kingdom. The same specific word can be used several times but with different genera.)

TAXONOMIC CATEGORIES:CATEGORY:A Category is a rank or level in the hierarchical classification of organisms. There are 7 obligate categories and some intermediate categories.

KINGDOM PROTISTA Includes all uniceliular eukaryotes.

(1) Cell walls are present in some organisms.

(2) Nuclear membrane is present.

(3) Body structure is cellular.

(4) Mode of nutrition is autotrophic (photosynthetic) and heterotrophic.

KINGDOM FUNGI constitute a unique kingdom of heterotrophic organisms.

(1) Cell type is eukaryotic.

(2) Cell wall is present (without cellulose)

(3) Nuclear membrane is present.

(4) These are multicellular.

(5) Mode of nutrition is heterotrophic (Saprophytic /parasitic)

KINGDOM PLANTAE includes all eukaryotic chlorophyll containing organisms.

(1) Cell wall is present. (Cellulose)

(2) Nuclear membrane is present.

(3) These organisms have tissue /

organ type of body organisation

(4) Mode of nutrition is Autotrophic (photosynthetic)

KINGDOM ANIMALIA includes heterotrophic eukaryotic organisms.

(1) Cell wall is absent.

(2) Nuclear membrane is present.

(3) Animals have tissue /organ/organ

system type of body organization.

(4) Mode of nutrition is heterotrophic

(holozoic/saprophytic)

LET US KNOW, WHAT WE HAVE LEARNT!

PART -A VERY SHORT ANSWER TYPE QUESTIONS

(a) - MULTIPLE CHOICE QUESTIONS

Q (1). In Five Kingdom system of classification organisms are divided into:-

(a) Monera, protista, algae, fungi and animalia

(b) Archia, protista, fungi, Plantae and animalia

(d) None of the above

Q (2) Two kingdom system of classification was proposed by:-

(a) Aristotle

(b) R.H.Whittaker

(d) None of the above

Q (3). All eukaryotic unicellular organisms belong to kingdom:-

(a) Monera,

(b) Protista

(d) Plantae

Q (4) Aristotla classified animals into :-

(a) Animals with red blood and without red blood

(b) Animals with white blood and without white blood

(d) None of the above

Q (5) According to five kingdom system of classification bacteria belong to:-

(a) Monera,

(b) Protista

(d) Plantae

(b) - FILL IN THE BLANKS

Q (1) Kingdom-—---—--includes all prokaryotic unicellular organisms.

Q (2) Cell wall is -—---— in plants.

(c) TRUE / FALSE

Q (1) All plants have heterotrophic mode of nutrition.

Q (2) Kingdom protista includes all unicellular eukaryotes.

Q (3) Prokaryotes are without definite nucleus.

ANSWER KEY

PART-A

(a) - MULTIPLE CHOICE QUESTIONS

Ans 1.(c) Monera, Protista, Fungi, Plantae and Animalia

Ans 2. (c) Linnaeus

Ans 3. (b) Protista (Well defined nucleus is present)

Ans 4. (a) Animals with red blood and without red blood

Ans 5. (a) Monera (Kingdom monera includes all unicellular prokaryotes)

(b) - FILL IN THE BLANKS

Ans 1. Monera (Kingdom Monera includes all unicellular prokaryotic organisms. )

Ans 2. Present (Plant cell wall is made up of cellulose. )

(c) - TRUE / FALSE

Ans 1. False (Green plants are autotrophs)

Ans 2. True (Kingdom Protista includes all unicellular eukaryotic organisms)

Ans 3. True (In prokaryotic organisms nuclear membrane is absent)

PART-B_ SHORT ANSWER TYPE QUESTIONS

Q (1) What is the need of biological classification?

Q (2) Write characteristics of kingdom Plantae.

Q (3) Write the criteria used by R.H. Whittaker for five kingdoms of life.

HIERARCHY OF CATEGORIES:It is system of arrangement of taxonomic categories in ascending order depending upon their relative dimensions. It was introduced by Linnaeus and is therefore also called Linnaean hierarchy for taxonomic hierarchy.(Linnaeus proposed five categories —class, order, genus, species and variety. Later workers deleted the category of variety and added the category of kingdom, Phylum (animals) or division (plants) and family. )Taxonomic categories which are always used in hierarchical classification of organisms are called obligate category.They are 7 in number (Kingdom, phylum or division, class, order, family, genus and species.) In order to make taxonomic position more precise, some intermediate categories sub Kingdom, super phylum or (super division), sub phylum (subdivision),super class, sub class, super order, super family, sub family, tribe, sub species or variety have been added.

1. SPECIES:It is the lowest or basic taxonomic category. Ernst Mayr defined Species as a group of individuals with similar morphological characters have a distant genetic setup, are able to breed among themselves to produce fertile offspring. E.g. Panthera leo,Panthera tigris. Here leo and tigris are species included in genus Panthera. Solanum nigrum, Solanum tuberosum, Solanum. Here nigrum, tuberosum and melongina are three species under genus Solanum. The term species was given by John Ray.

2. GENUS:It is a group of related species which has more character in common in comparison to species or other genera. E.g. Tomato (Solanum lycopercicum), potato (Solanum tuberosum), brinjal (Solanum melongena) are three species belonging to genus Solanum. Lion (Panthera leo), leopard (Panthera pardus) and tiger (Panthera tigris) are all species of genus Panthera. This genus differ from another genus Felis which

includes cats.

3. FAMILY:Family has a group of related genera with still less number of similarities as compared to genus and species. Families are formed on the basis of both vegetative and reproductive features of plant species e.g. Among plants, three different genera Solanum, Petunia and Datura are placed in family Solanaceae.In animals genus Panthera having lion, tiger, leopard is put along with the genus,Felis (Cats) in family Felidae. Dogs are placed in family Canidae.

4. ORDER:It is a group of families which show a few similar characters. The similar characters are less in number as compared to different genera included in family. Piant families like Convolvulaceae, Solanaceae are included in order Polymoniales mainly based on the floral characters. The animal order, Carnivora includes family like Felidae and Canidae.

5. CLASS:This category includes related orders e.g. order Primata which has man, monkey and apes is placed in class Mammalia along with order Carnivora that include animals like tiger, cat and dog. Class Mammalia has other orders also.

6. PHYLUM:The term phylum is used for animals while term division (Eichler) is used for plants.A phylum or division consist of one or several related classes having similar co-related characters e.g. Phylum Chordata consists of many classes like Pisces ,Amphibia, Reptiles, Aves, Mammais etc.

7. KINGDOM:All animals belonging to various phyla are placed in highest category called Kingdom Animalia. Kingdom Plantae has all plants from various divisions.As we go higher from Species to Kingdom, the number of common characteristics goes on decreasing. Lower the Taxa, more common characters are shared by members. Higher the category, fewer common characters are shared by members.The number of organisms increase as we move from Species to Kingdom.

TAXON:Mayr has defined Taxon as a Taxonomic group of any rank which can be assigned to a definite category. Taxon represent real biological objects placed in any category.Category itself is an abstract term.

ORGANISMS WITH THEIR TAXONOMIC CATEGORIES:names Kingdom

“LET'S KNOW WHAT WE LEARN?"

1. VERY SHORT ANSWER TYPE QUESTIONS:

PART A MULTIPLE CHOICE QUESTIONS :

1. A Species is a a group of organisms which

(a) can interbreed freely

(b) do not interbreed

(d) can interbreed occasionally

2. A group of interconnected genera is called a

(a) Family.

(b) Class

(d) Order

3. Arrange the following in Linnaean hierarchy.

(a) Kingdom-Order-Species-Genus-Class-Family-Phylum

(b) Kingdom-Family-Genus-Species-Class-Phylum-Order

(d) Species-Genus-F amily-Order-Class-Phylum-Kingdom

4. The genus Felis includes :

(a) Tiger.

(b) Fish

(d) Frog

5. Primata and Carnivora are placed together in same

(a) Order.

(b) Division

(d) Class

PART B- FILL IN BLANK:

1. proposed system of taxonomic categories in ascending order .

2. The term is used for animals while term is used for plants.

3. All animals belonging to various phyla are placed in highest category called Kingdom

PART C- TRUE/ FALSE:

1. As we go higher from species to Kingdom, the number of common characteristics goes on increasing. T/F

2. Order is group of families which show a few similar characters, T/F

3. A category is a rank or level in the hierarchical classification of organisms. T/F

2. SHORT ANSWER TYPE QUESTIONS:

1. Write the scientific name of Human and Mango.

2. Define Species. Who coined the term Species?

3. Give two difference between Taxon and Category.

3. LONG ANSWER TYPE QUESTION:

1. Illustrate the taxonomical hierarchy with suitable example of a plant and an animal

ANSWER KEY OF MULTIPLE CHOICE QUESTIONS:

1. a (Species) Hint: Species as a group of individuals with similar morphologicalcharacters have a distant genetic setup, are able to breed among themselves to produce fertile offspring. E.g. Panthera leo,

2. a (Family) HINT: Family has a group of related genera with still less number of similarities as compared to genus and species.

3. d (Species-Genus-F amily-Order-Class-Phylum-Kingdom)

HINT: They are 7 in number (Kingdom, phylum or division, class, order, family,genus and species.) In order to make taxonomic position more precise, some intermediate categories sub Kingdom, super phylum or (super division), sub phylum (subdivision), super class, sub class, super order, super family, sub family, tribe, sub species or variety have been added.

4. c (Cat) HINT: In animals genus Panthera having lion, tiger, leopard is put along with the genus, Felis (Cats) in family Felidae.

5. d (Class) HINT: This category includes related orders e.g. order Primata which has man, monkey and apes is placed in class Mammalia along with order Carnivora that include animals like tiger, cat and dog. Class Mammalia has other orders also.

ANSWER KEY OF FILL IN THE BLANK:

1. Linnaeus

HINT: It is system of arrangement of taxonomic categories in ascending order depending upon their relative dimensions. It was introduced by Linnaeus and is therefore also called Linnaean hierarchy for taxonomic hierarchy.

2. Phylum and Division

HINT: The term phylum is used for animals while term division is used for plants.

3. Animalia

HINT: All animals belonging to various phyla are placed in highest category called Kingdom Animalia.

ANSWER KEY OF TRUE / FALSE:

1. FALSE (HINT: As we go higher from Species to Kingdom, the number of common characteristics goes on decreasing. Lower the Taxa, more common characters are shared by members.)

2. TRUE (HINT: Order is a group of families which show a few similar characters.The similar characters are less in number as compared to different genera included in family. Plant families like Convolvulaceae, Solanaceae are included in order Polymoniales mainly based on the floral characters. The animal order, Carnivora

includes family like Felidae and Canidae.)

3. TRUE (HINT: A Category is a rank or level in the hierarchical classification of organisms. There are 7 obligate categories and some intermediate categories.)

Taxonomic Aids: Taxonomic aids/tools are collections of samples of preserved organisms or any kind of storage of information that can help in identification as well as Classification of organisms. Different components of these aids are as follows:

1. Herbarium: Itis a place where dried and pressed plants’ specimens, mounted on sheets, are kept systematically according to the natural system of classification. It is a store house for future use. Every educational institute as school, college or university, has a small or large herbarium. Students are trained to collect and identify plant specimens (local plants) and prepare herbarium sheets.

Tools required for plant collection and preservation:

i) Digger: For taking out roots,rhizomes, bulbs, tubers etc.

ii) Pair of large scissors:For cutting twigs.

iii) Knife: For cutting hard woody twigs.

iv) Sickle with long handle:For cutting twigs of tall trees.

v) Vasculum Box: It is used to temporarily store fresh shoots. It is 45-60 cm long,20 cm wide and 15 cm deep.Polythene bags can be used for this purpose.

vi) Plant Press: It consists of wooden boards in which herbarium sheets are kept and is used to press the plants.

vii) Herbarium Sheet: It is a simple piece of paper where the dried plant specimen is mounted with the help of glue or cello tape. Size of the sheet may be 29x41 cm or 30x45cm. —

iii) Blotting papers: These are used to dehydrate the plant specimen.

Procedure: 25- 35 cm long plant with roots, stem, leaves, flowers and/or fruits (in case of an herb) or a shoot with leaves, flowers and fruits (if it is a shrub or a tree) is taken. It is properly spread over blotting paper exposing all parts of it unfolded.Blotting papers with plant specimens are then placed in plant press and kept for slow dehydration. After drying, these specimens are pasted on herbarium sheets with glue or cello tape. Labelling of specimen’s scientific name, local name,collector's name, place, time and date of collection is done.

2. Botanical Gardens: It is an enclosed piece of land where Collection,cultivation, preservation and display of a wide range of plants labelled with their scientific names is done. There are over 525 large sized botanical gardens developed in various parts of the world. The most famous garden of the world is Kew Garden or Royal Botanical Garden, Kew (London). Some large sized Indian

botanical gardens are as follows:

i) Indian Botanical Garden Howrah-Kolkata (Sibpur).

ii) National Botanical Garden, Lucknow.

iii) Llyod Botanical Garden, Darjeeling.

3. Museums:A museum is a building or a place that preserves a collection of fossils and other objects of artistic, cultural, historical, or scientific importance. All educational institutes and universities maintain museums in their botany and zoology departments. Museum of natural history has collection of preserved plants and animals. Only those plants are preserved in museums which cannot

be kept in herbaria e.g., algae, fungi, mosses, ferns, parts of gymnosperms,fruits, underground storage organs etc. These specimens are preserved in solution of alcohol and formalin. Many animal specimens e.g., worms, insects,fishes and reptiles can also be kept in preservative solutions in jars. Insects can be dried out and mounted in boxes. Larger animals are preserved in stuffed and skeleton forms. Names of some important museums are listed as follows:

i) American Museum of Natural History, New York, U.S.A.

ii) State Museum of Natural History, Stuttgart, Germany.

iii) Museum of natural history, Basel, Switzerland.

iv) Bird Collection Museum of Natural History, Vienna, Austria.

v) National Museum of Natural History, Paris.

vi) National Museum of Natural History, Baraknamba Road, New Delhi.

vii) Museum of Arthropoda, Shaniwar Petu, Pune.

4. Zoological Parks:These are enclosed areas of land where animals are kept in open boundaries.Zoological parks or zoological gardens provide more natural environment to animals than zoos. There are more than 1500 Zoos in the world. In India, there are 200 zoos and zoological parks looked after by a Central Zoo Authority.Some states of India maintain large aquaria (for fishes, e.g., Mumbai), aviaries

(for birds) and serpentariums (for snakes, e.g., Chennai) .

Role of Zoological parks: Zoological parks are useful for:

e Familiarizing public, especially children, with wild animals.

e The students in studying behavior of different animals.

e Attracting tourists.

e Conservation through captive breeding of endangered animals.

5. Taxonomic Key:It is a scheme for identification of plants and animals based on their similarities and dissimilarities. In a taxonomic key, there is a series of questions about the

organism's physical characteristics. The answer will either branch off to another question or will identify an unknown organism. With the help of it, one can quickly find out the name of the organism.

Types: The keys are of two types:

a) Indented Key: It gives two or more alternate characteristics which are used to make choice by rejecting or selecting.

b) Bracketed Key: Here, the key does not separate by characters but

subdivides the characters by giving them numbers in brackets.

Example to identify six vertebrates- fish, frog, snake, bat and cat, with the help of both types of keys is as follows:

LET US KNOW WHAT WE LEARN?

A) Very Short Answer Type Questions: -

a) Multiple Choice Questions: -

1) Botanical gardens provide

(a) Natural habitat to wild life

(b) Beautiful area for recreation

(d) Repository of tropical plants

2) Out of the following which provides information regarding

animal behavior, adaptation, nutrition and ecology?

(a) Herbarium

(b) Zoological park

(d) Museum

3) Fossils are preserved in

(a) Zoos

(b) Botanical gardens

(d) Museums

4) Aplace of collection of dried plant specimens is

(a) Botanical garden

(b) Herbarium

(d) All above

5) Kew, London is famous for being one of the largest

(a) Herbarium

(b) National park

(d) Zoo

b) True/False: -

1) Fruits can be preserved in museums. T/F

2) Zoological parks provide more natural environment to the animals. T/F

3) Larger animals are preserved in stuffed and skeletal forms in museums. T/F

c) Fill in the blanks: -

1) Museums have collections of plantsand_ tt.

2) An organism with external ears absent but wings presentcanbea__.

B) Short Answer Type Questions: -

1) Define Taxonomic Key. Name its types.

2) What are museums? Name any one of the important museums of India.

3) Name the tools used for collection and for preservation of plants for an herbarium.

Answer Key: -

a) Multiple Choice Questions: -

1) (c); Ex situ conservation of germplasm

2) (b); Zoological park

3) (d); Museums

4) (b); Herbarium

5) (a); Herbarium

b) Fill in the blanks: -

1) animals

2) bird

c) True/False: -

1) False

2) True

RECAPITULATION:In this chapter of ‘The Living world’, we learnt about:

i) Characteristics of Living Beings; definite shape and size, organization,homoeostasis, protoplasm, cellular structure, genetic material, variations, strugg]for existence, adaptations, evolution, reproduction, growth, death, life cycle, self regulation, movements, coordination, metabolism, consciousness and irritability,healing and regeneration.

ii) Diversity in the Living World; nomenclature, common names, scientific names an rules for binomial nomenclature.

iii) Taxonomy; identification and classification.

iv) Taxonomic Categories; hierarchy (Species, Genus, Family, Order, Class, Phylum or Division and Kingdom) and taxon.

v) Taxonomic Aids/ Tools; herbarium, botanical gardens, museums, Zoological park and taxonomic key (indented and bracketed).

“Let Us Know What We Have Learnt”

Practice Questions with Solutions (NCERT):

1) Why are living organisms classified?

Solution: The earth consists of organisms, and we may know the plants and animal that live near us by their native names. These local names vary from place to place within a country. This may lead to confusion in identifying and studying specifispecies. Therefore, it must be called by common name throughout the world tstandardize the nomenclature and study of organisms. To achieve this, organisms ar named and categorized according to their roles.

2) Why are the classification systems changing every now and then?

Solution: Scientific study is ever a work in progress and new species and organism are often added. The initial system of classification focusses on habit and habitat oorganisms. Gradually external morphology became a toll for classification. After this,the morphology and embryology are taken into account, followed by the phylogenetic relationship, the cytology of the organism. Modern-day uses biochemical technique to classify the organisms based on their nucleic acid components.

3) What different criteria would you choose to classify people that you mee often?

Solution: The people we meet most often are categorized by characteristics a follows:

(i) Gender

(ii) Age

(iii) Height

(iv) Weight

(v) Classmates

(vi)Skin colour

(vii) Education

(viii) Career

(ix) Hobbies

(x) Nature

4. What do we learn from the identification of individuals and populations?

Solution: a) Identification of Individuals: Each individual possesses certain specifivariations in traits not found in other individuals of the same family or group.

b) Identification of Populations:

(i) Each population comprises individuals which resemble one another mor closely than individuals of other species.

(ii) Members of a population interbreed freely.

(iii) Members of a population share the same gene pool and have a distinc genetic set up.

(iv) Members of a population are reproductively isolated from individuals of othe species/ population found in the area.

5. Given below is the scientific name of Mango. Identify the correctly written name.Mangjifera Indica Mangjifera indica

Solution: The answer is Mangifera indica. Here, mangifera is its genus name, and indica is its species name which is always in lowercase.

6. Define a taxon. Give some examples of taxa at different hierarchical levels.

Solution: - Ataxonis a grouping of organisms of any level in hierarchical classification which is based on some common characteristics, e.g., Tiger, Eucalyptus, orchids,Lizards, Insects, Mammals, Roundworms, Birds, Fishes, Ferns, Algae, Grasses.

Insects represent a class of phylum Arthropoda. All the insects possess common character of three pairs of jointed legs. Any level in the given hierarchy level is termed as a ‘taxon’. The term taxon was introduced by ICBN (International Code of Botanical Nomenclature) in 1956.

Following are the hierarchical levels:

i) Kingdom

ii) Phylum

iii) Class

iv) Order

v) Family

vi) Genus

vii) Species

7. Can you identify the correct sequence of taxonomical categories?

a) Species Order Phylum Kingdom

b) Genus Species Order Kingdom

c) Species Genus Order Phylum

Solution: From the given options (a) and (c) is the correct sequence of taxonomical categories.

8. Try to collect all the currently accepted meanings for the word ‘species’.Discuss with your teacher the meaning of species in case of higher plants and animals on one hand and bacteria on the other hand.

Solution: A group of individual organisms with basic similarities is called species. This is the basic unit of classification. Species are defined as individuals who share the same gene pool.Higher plants and animals: Criteria of reproductive isolation can be used to classify

the species.Bacteria: interbreeding and reproductive isolation cannot be used in case of bacteria here gene pool can be used to classify species.

9) Define and understand the following terms:

(i) Phylum

(ii) Class

(iii) Family

(iv) Order

(v) Genus.

Solution:i) Phylum is a taxonomical hierarchy below Kingdom and above Class. Itis a taxon with one or more classes organisms with similar characters.

ii) Class is a taxonomical hierarchy higher than Order and lower than Phylum.Class includes related to orders of the organisms. Example: Presence of notochord in mammals.

iii) Family has a group of related genera with still less number of similarities as compared to genus and species. Example: Fox and dog belong to the same family. It is a group of entities below Order and above Genus.

iv) Order is a taxon below higher than Family and lowers than class. Order being a higher category is the assemblage of families which exhibit a few similar characters.

v) Genus comprises a group of related species which has more characters in common in comparison to species of other genera.Ex: Lion, tiger and leopard are classified under genus Panthera.It is above species and below Family.

10. How is key helpful in the identification and classification of an organism?

Solution: - The key is a taxonomic aid used to identify plants and animals, based on similarities and dissimilarities. It represents the choice between two opposite characters. This is useful for identifying contrasting characters. They are two contrasting characters, where one character's choice rejects another when the species, family, or genera is identified.If the entity is not already recorded, efforts are made for the first verification and reconsider its discovery before naming it. Therefore, each entity can be classified a it is known or unknown.

11. Illustrate the taxonomical hierarchy with suitable examples of a plant and an animal.

Solution: - Taxonomical hierarchy is given as below:

1. Kingdom

Subkingdom

2. Phylum or Division

Sub-phylum or Sub-division

3. Class

Sub-class

Super-order

4. Order

Sub-order

Soper-family