1st PUC Biology Question Bank Chapter 1 The Living World

Karnataka 1st PUC Biology Question Bank Chapter 1 The Living World

1st PUC Biology The Living World One Marks Questions and Answers

Question 1.
Name the basic unit of classification.
Answer:
Species.

Question 2.
Define species.
Answer:
Species is the lowest level of organization and organisms belonging to a particular species have similar morphological, anatomical & physiological characters and can interbreed to produce fertile offsprings. .

Question 3.
Who is the father of taxonomy?
Answer:
Carolus Linnaeus.

Question 4.
What is a taxon?
Answer:
Any classification group, category or rank is called a taxon.

Question 5.
Write the scientific name of coconut.
Answer:
Cocos nucifera.

Question 6.
What is a key?
Answer:
A key is an analytical scheme for identification of plants and animals, based on of the similar-ities and differences.

Question 7.
Name the scientific method of naming a species used by Carolus Linnaeus?
Answer:
Binomial Nomenclature.

Question 8.
Why are living organisms classified?
Answer:
Classification is necessary for study of all living organisms by grouping them conveniently into categories , based on some easily observable characters.

Question 9.
Why are the classification systems changing every now and then?
Answer:
New organisms are being found by extensive research and new technology. Some organisms in course of time become extinct. So to accommodate these facts under classification, changes are made now and then.

Question 10.
Given below is the scientific name of Mango. Identify the correctly written name.
(a) Mangifera Indica
(b) Mangifera indica
Answer:
(b) Mangifera indica

Question 11.
What does ICZN stand for?
Answer:
International Code of Zoological Nomenclature.

Question 12.
Couplet in taxonomic key means
Answer:
Pair of alternate characters.

Question 13.
What is monograph?
Answer:
Monographs: Monographs give a comprehensive account of complete compilation of available information of any one family or genus at a time.

Question 14.
Define metabolism.
Answer:
It is the sum total of all molecular interactions that occur inside living organisms. ‘

Question 15.
Name the structural and functional unit of an organism.
Answer:
Cell is the structural and functional unit of an organism.

Question 16.
What is binomial nomenclature?
Answer:
Naming of living’organisms by scientific name universally by two names is binominal nomenclature. The two names include generic name and species name

Question 17.
Who introduced the binomial nomenclature?
Answer:
Carious Linnaeus.

Question 18.
Name the basic unit of classification.
Answer:
Species is the basic unit of classification.

Question 19.
What is taxonomy?
Answer:
Identification, nomenclature and classification of an organism is called taxonomy.

Question 20.
What is taxon?
Answer:
Classification unit in Linnaean hierarchy is called taxon.

Question 21.
What is taxonomic category?
Answer:
Each step or rank in the hierarchy is called taxonomic category.

Question 22.
What is taxonomic hierarchy?
Answer:
All successive taxonomic categories are taxonomic hierarchy.

Question 23.
Define species.
Answer:
A group of individual organisms with fundamental similarities (i.e. in morphology, anatomy and physiology) abd capable of breeding among themselves is called a species.

Question 24.
Define genus.
Answer:
Genus comprises of a group of related species.

Question 25.
Define family.
Answer:
A family is a group of related genera.

Question 26.
Define order.
Answer:
Group of closely related families.

Question 27.
Define class.
Answer:
Group of closely related orders.

Question 28.
Define phylum.
Answer:
Phylum is a category higher to class and it consists of different classes with a few similar characters. In animals, closely related classes form a phylum.

Question 29.
Define division.
Answer:
Division is a higher category and it consists of different phylums with a few similar characters. In plants closely related phylums form a division.

Question 30.
Define Kingdom.
Answer:
Kingdom is the highest category in the hierarchy. Animal kingdom comprises of all the animal phyla.

Question 31.
What are zoos?
Answer:
These are the places where wild animals are kept in a protected environment, and are provided with food shelter and change for mating.

1st PUC Biology The Living World Two Marks Questions and Answers

Question 1.
What do we learn from identification of individuals and populations?
Answer:
By identification of individuals/populations one can learn about their life-style, geographical habitation, culture, social and economic status, language, food ( habits), beliefs and their effect on other people/population.

Question 2.
How is a key helpful in the identification and classification of an organism?
Answer:
Keys are contrasting pair of characters (couplet). It represents the choice made between two opposite options. This results in the acceptance of only one of them and rejection of the other. Each statement in the key is called a lead. Separate taxonomic keys are required for each taxonomic category such as family, genus and species for identification purpose.

Question 3.
Mention any four characters of living organisms.
Answer:
The living organisms are characterized by the following features:
(a) Growth
(b) Reproduction
(c) Metabolism
(d) Cellular organization.

Question 4.
Mention any four taxonomical aids which help in preserving specimens.
Answer:
Four widely used taxonomical aids are,
(a) Herbarium.
(b) Botanical gardens.
(c) Museum.
(d) Zoological parks.

Question 5.
What is a herbarium? How herbarium help in preserving plant specimens?
Answer:
Herbarium is a store house of collected plant specimens that are dried, pressed, and preserved on sheets.
(a) Herbarium sheets are arranged according to a universally accepted system of classification.
(b) These specimens along with their descriptions on herbarium sheets become a store house.
(c) The herbarium sheets also carry a label providing information about the date and place of collection, English, local, and botanical names, family and the collector’s names.
(d) Herbaria serve as quick referral systems in taxonomical studies.

Question 6.
What is a Botanical garden? Give examples.
Answer:
These are specialised gardens which have collections of living plants for reference plant species in botanical gardens are grown for identification purposes and each plant is labelled by indicating its botanical name and family. e.g:
1. Kew (England).
2. Indian Botanical Garden – Howrah.
3. National Botanical Research Institute – Lucknow.
4. Lalbhagh Botanical Garden – Bangalore.

1st PUC Biology The Living World Three Marks Questions and Answers

Question 1.
Illustrate the taxonomical hierarchy with suitable examples of a plant and an animal.
Answer:
Plant – Mango
Kingdom – Plantae
Phylum – Tracheophyta
Class – Dicotyledonae
Order – Sapindales
Family – Animalia
Genus – Mangqera
Species – indica

Animal:
Animal – Man
Kingdom – Animalia
Phylum – Chordata
Class – Mammalia
Order – Primata
Family – Hominidae
Genus – Homo
Species – sapiens

Question 2.
(a) What an taxonomic aids?
(b) Give the importance of herbaria and museums,
(c) How are Botanical Gardens and Zoological Parks useful in conserving biodiversity?
Answer:
(i) Herbarium:
A herbarium is defined as a collection of plants, that have been dried, pressed and preserved on sheets.
These sheets are arranged in accordance with any accepted system of classification. They can be used for future references.

(ii) Botanical Gardens:
These are collections of living plants maintained for reference, i.e., they are meant for identification and classification. Both local and exotic plants are grown.
* These are considered natural and economical reference systems.
* Following are some famous botanical gardens in India.
1. Indian Botanical Garden, Howrah.
2. National Botanical Research Institute, Lucknow.

(iii) Museums:

Museums are those places which have collections of preserved animals and plants for taxonomic studies.
The plant and animal specimens are kept in chemical solutions of formalin, and are preserved for a longer duration.
Plant and animal specimens may also be preserved as dry specimens.
Insects are preserved in insect boxes. The collected insects are dried and pinned in these boxes.
Larger animals like birds and mammals are usually preserved as stuffed specimens.
Skeletons,of animals are also collected in the museums.
The specimens have been correctly identified, labelled and stored.
A catalogue of specimens is prepared for future use. …

(iv) Zoological Parks:

These are the places where wild animals are protected in conditions very similar to their natural habitats. Food and shelter is provided. Health of the animal is monitored and chance for reproduction (mating) is given.
The scientific purpose of such parks is to breed animals under captivity to avoid extinction.

Question 3.
Define a taxon. Give some examples of taxa at different hierarchical levels.
Answer:
Taxon is a unit of classification or a rank or a level or hierarchy in system of classification. The following chart giving taxonomical categories showing hierarchical arrangement the in descending order.
The system of arrangement of different taxonomic categories during classification, is called hierarchy of categories (Linnaeus)

(i) Species : It is a group of individuals with similar morphological characters and who can freely interbreed among themselves, to produce fertile offsprings of their own kind. The individuals of a species also represent a population of that species in a given place, H and do not breed with individuals of other species, i.e., reproductively isolated,

(ii) Genus : Genus is a group of related species, that have more characters in common as compared to individuals of species of other genera, e.g. potato and brinjal belong, to the genus Solarium (S. tuberosum and S. melongena respectively). Lion, leopard and tiger ’ belong, to the genus Panthera (P. leo, P. pardus arid P. tigris respectively).

(iii) Family: Family represents group of related genera, that are more similar to each other than with the genera of other families e.g. Petunia, Solanum and Atropa belong to the family Solanaceae.

(iv) Order: An order is an assemblage of families related to one another in a few characters. e.g. Solanaceae and Convolvulaceae belong to the order Polemoniales, Felidae and Canidae belong to the order Carnivora.

(v) Class : A class represents organisms of related orders, e.g. Carnivora and Primata belong to class Mammalia.

(vi) Phylum : A phylum includes all organisms belonging to different classes having a few characters in common, e.g. Phylum Chordata includes these classes: Osteichthyes, Chondrichthyes, Amphibia, Reptilia, Aves and Mammalia.

(vii) Kingdom: A kingdom includes all organisms that share a set of distinguishing characters. e.g. All plants (algae, biyophytes, pteridophytes, gymnosperms and angiosperms) are included in the Kingdom Plantae. The following table shows the systematic position of four examples.

Common Name	Mango	Human(being)	Wheat	Housefly
Kingdom	Plantae	Animalia	Plantae	Animalia
Phylum	Tracheophyta	Chordata	Angiospermae	Arthropoda
Class	Dicotyledonae	Mammalia	Monocotyledonae	Insecta
Order	Sapindales	Primata	Poales	Diptera
Family	Anacardiaceae	Hominidae	Poaceae	Muscidae
Genus	Mangifera	Homo	Triticum	Musca
Species	indica	sapiens	aestivum	domestica

1st PUC Biology The Living World Five Marks Questions and Answers

Question 1.
Write a short note on Binomial Nomenclature and guidelines for Binomial Nomenclature.
Answer:
Guidelines/Principles for nomenclature:
(i) Scientific names are, generally, written in Latin or derived from Latin, irrespective of their origin.
(ii) The sctentific names are written in Italics or underlined. The first-word denotes the name of the genus, and the second word denotes the species.
(iii) The generic name starts with a capital letter, while the specific name starts with a small letter.
(iv) The name of the author is written in an abbreviated form after the specific name e.g. Mang(fera indica Linn.-indicates that this species was first described by Linnaeus.
(v) The name should be short, precise and easy to pronounce.

Question 2.
Mention various Taxonomic aids and briefly describe them.
Answer:
The collection of specimens which help in the identification of a species are called taxonomic aids. Some of the major taxonomic aids are:

(i) Herbarium: A herbarium is defined as a collection of plants that have been dried, pressed and preserved on sheets. These sheets are arranged in accordance with any accepted system of classification and they form a repository for future use. Date and place at collection is marked on sheets.

(ii) Botanical Gardens: These specialized gardens have collections of living plants for reference. Plant species in these gardens are grown for identification purposes and each plant is labelled indicating its scientific name and its family.

(iii) Museum : Museums are those places which have collection of preserved animals and plants for taxonomic studies.

(iv) Zoological parks: These are places which have wild animals kept in protected environments under human care and which enable us to learn about their food habits and behaviour.

(v) Keys: A key is an analytical scheme for identification of plants and animals based on the similarities and differences.

Question 3.
Describe the steps involved in the classification of an organism.
Answer:
The following are steps involved in classifying an organism,
(a) The organism has to be described for all its morphological and other characteristics.
(b) Based cm its characteristics, it is identified for its similarities and differences to any known group or taxon.
(c) It is then placed in a known taxon based on its similar characters.
(d) If it different from the zones already described anywhere in the world, it is placed in a new group and then given a new name (in latin).
(e) If the organism has not been described before, it is given a new name; or its correct name is determined.

Question 4.
Write a short note on Keys.
Answer:
A key is an analytical scheme for identification of plants and animals based on the similarities and differences. The keys are based on the contrasting characters, generally in a pair called couplet.
Each couplet actually represents the choice made between two opposite options, leading to the acceptance of one. Each statement in the key is called a lead keys are of two types:-

Indented keys : which provides a sequence of choices between two or more statements of character of species.
Bracketed keys : where pairs of contradicting characters are used for identification, the number on the right of the statement indicate the recent choice of paired contrasting statements.

Question 5.
Write a note on Flora, Manuals and Monograph.
Answer:
Monographs: Monographs give a comprehensive account of complete compilation of available information of any one family or genus at a time.

Manuals: Manuals contain compiled or complete information about the particular area, key, descriptions of families, genus and species.

Flora: Flora contains the actual description of the habitat and distribution of plants in a given area. We have several fleas in India. e.g. Flora of India, Flora of Karnataka, Flora of Delhi, Flora of Madras, etc.

1st PUC Biology The Living World Text Book Questions and Answers

Question 1.
What is ‘LIVING’?
Answer:
It is difficult to define living beings or their property of life or living but there are certain distinctive characteristics exhibited by living organisms.
Such characteristics distinguish the living from the non-living these include:
(i) Growth
(ii) Reproduction
(iii) Metabolism
(iv) Ability to sense the surroundings and respond on to stimuli.
(i) Growth: Growth is defined as an irreversible increase in the number of cells and/or mass of the living structure. In plants, growth occurs continuously throughout the life. In animals, growth is restricted to a certain period only, but cell divisions occur in certain tissues to replace the old and worn out cells.

(ii) Reproduction: Unicellular organisms reproduce by cell division, usually mitosis. In multicellular organisms, reproduction refers to the production of young ones of the same kind.

(iii) Metabolism: Metabolism refers to the sum of all the chemical reactions occurring in a living body.

(iii) Response, to stimuli: All the organisms, ie, prokaryotes or eukaryotes, simple or complex in organisation, have the ability to sense the conditions in their surroundings and respond to these stimuli. Such stimuli may be physical, chemical or biological. Photo period affects reproduction in several seasonal breeders of animals as well as flowering in plants. Stems of plants bend towards light, while roots bend towards water sources and gravitational pull.

2. Biodiversity:

Biodiversity refers to the variety of organisms present on the Earth, (species richness)
The number of species known to man and described is about 1.7 to 1.8 million.

3. Need And Scope Of Taxonomy:
Taxonomy is the identification, nomenclature and the arrangement of organisms based on certain principles, (taxis-arrangement: nomos : principle)

Taxonomy of organisms is based on the knowledge of the following: –
(i) Form and structure (morphology).
(ii) Cell structure (cytology).
(iii) Developmental processes (embryology).
(iv) Remnants of the past organisms (fossils) and
(v) Ecological relationship.

4. Identification:

Identification of an organism is carried out to determine its similarity with known organisms.

5. Nomenclature:

Once the organism is fully described, it is given a scientific name.
Names are based on certain observable/morphological and distinct characters as well as the similarities with an already known organism.
Scientists/biologists have established procedures, to assign a scientific name to each known organism.
Since the scientific names are based on agreed principles and criteria, they are acceptable all over the world.
The rules of nomenclature are provided in the International Code of Botanical Nomenclature (ICBN) for plants and in the International Code of Zoological Nomenclature (1CZN) for animals.
The scientific names are unique to species and are universal.

(a) Binomial Nomenclature:
This method was introduced by Carolus Linnaeus. In this method, every organism is given a scientific name, which has two parts, the first is the name of the genus (generic name) and the second is the name of the species (specific epithet). e.g. Mangifera indica for mangoes and Homo sapiens for human beings. In the above, Mangifera and Homo are generic names, while indica and sapiens are the names of the species belonging to Mangifera and Homo respectively.

Classification consists of a hierarchy of steps where each step represents a range or category. The various ranges or categories used in classification are called Taxonomic categories.

(b) Guidelines/Principles for nomenclature:
(i) Scientific names are, generally, written in Latin or derived from Latin, irrespective of their origin.
(ii) The scientific names are written in Italics or underlined. The first-word denotes the name of the genus, and the second word denotes the species.
(iii) The generic name starts with a capital letter, while the specific name starts with a small letter.
(iv) The name of the author is written in an abbreviated form after the specific name e.g, Mangifera indica Linn.-indicates that this species was first described by Linnaeus,
(v) The name should be short, precise and easy to pronounce.

6. Classification:
• Once the organism is identified and given a name, it is grouped along with similar ones.
• The following steps are involved in classifying an organism.
(i) The organism has to be described for all its morphological and other characteristics.
(ii) Based on its characteristics, it is identified for its similarities or differences to any other known group or taxon.
(iii) It is then placed in a known taxon, based on its similar characters.
(iv) If it is different from the ones already described anywhere in the world, it is placed in a new group and then given a name for the group.
(v) If the organism has not beat described before it is given a new name.
Thus characterisation, identification, classification and nomenclature are the processes that are the basis to taxonomy.

7. Taxonomic Hierarchy / Taxonomic Categories:

Species is the basic unit of classification.
Kingdom is the highest category/unit in classification.

In the plant Kingdom, division is the category, equivalent to phylum in animal kingdom and cohort is used in place of order. All the members of a taxon have similar characteristics, which are different from that of other taxa. Higher the category, lesser will be the number of similar characteristics of organisms belonging to that category.

The system of arrangement of different taxonomic categories during classification, is called hierarchy of categories (Linnaeus)

(i) Species : It is a group of individuals with similar morphological characters and who can freely interbreed among themselves, to produce fertile offsprings of their own kind. The individuals of a species also represent a population of that species in a given place. H and do not breed with individuals of other species, i.e., reproductively isolated,

(iii) Family: Family represents group of related genera, that are more similar to each other than with the genera of other families e.g. Petunia, Solanum and Atropa belong to the family Solanaceae.

(v) Class : A class represents organisms of related orders, e.g. Carnivora and Primata belong to class Mammalia.

Common Name	Mango	Human(being)	Wheat	Housefly
Kingdom	Plantae	Animalia .	Plantae	Animalia
Phylum	Tracheophyta	Chordata	Angiospermae	Arthropoda
Class	Dicotyledonae	Mammalia	Monocotyledonae	Insecta
Order	Sapindales	Primata	Poales	Diptera
Family	Anacardiaceae	Hominidae	Poaceae	Muscidae
Genus	Mangifera	Homo	Triticum	Musca
Species	indica	sapiens	aestivum	domestica

8. Taxonomic Aids:
All those collections of actual live specimens or preserved specimens, which help in the identification or verification of a species, are called taxonomic aids.

Some of them include,
(i) Herbarium
(ii) Botanical Gardens
(iii) Museums
(iv) Zoological Parks
(v) Keys
(vi) Monographs
(vii) Manuals
(viii) Floras.
(i) Herbarium:
A herbarium is defined as a collection of plants, that have been dried, pressed and preserved on sheets.
These sheets are arranged in accordance with any accepted system of classification. They can be used for future references.

(iii) Museums:

Museums are those places which have collections of preserved animals and plants for taxonomic studies.
The plant and animal specimens are kept in chemical solutions of formalin, and are preserved for a longer duration.
Plant and animal specimens may also be preserved as dry specimens.
Insects are preserved in insect boxes. The collected insects are dried and pinned in these boxes.
Larger animals like birds and mammals are usually preserved as stuffed specimens.
Skeletons,of animals are also collected in the museums.
The specimens have been correctly identified, labelled and stored.
A catalogue of specimens is prepared for future use. …

(iv) Zoological Parks:

These are the places where wild animals are protected in conditions very similar to their natural habitats. Food and shelter is provided. Health of the animal is monitored and chance for reproduction (mating) is given.
The scientific purpose of such parks is to breed animals under captivity to avoid extinction.

(v) Keys:

A key is an analytical scheme for identification of plants and animals based on the similarities and differences.
The keys are based on the contrasting characters, generally in a pair, called couplet.
Each couplet actually represents the choice made between two opposite options, leading to the acceptance of one.
Each statement in the key is called a lead.

(vi) Monographs : Monographs give a comprehensive account of complete compilation of available information of any one family or genus at a time.

(vii) Manuals: Manuals contain compiled or complete information about the particular area, key, descriptions of families, genus and species.

(viii) Flora: Flora contains the actual description of the habitat and distribution of plants in a given area. We have several floras in India, e.g. Flora of India, Flora of Karnataka, Flora of Delhi, Flora of Madras, etc.