Introduction
"The Living World," serves as an intriguing exploration into the fascinating realm of life and living organisms. This chapter delves into various aspects of life, ranging from the definition of what constitutes living entities to the diverse forms of life found on Earth. Through the exploration of concepts such as diversity in the living world and taxonomic categories, students embark on a journey to understand the complexity and unity of life.
1.1 What is Living?
In section 1.1, the chapter delves into the fundamental question: what defines life? Through an examination of the characteristics of living organisms, students gain insights into the distinguishing features that separate living entities from non-living matter.
1.2 Diversity in the Living World
Section 1.2 explores the vast diversity of life forms found on our planet. From microscopic bacteria to towering trees, the chapter showcases the incredible variety of living organisms and their adaptations to diverse environments.
1.3 Taxonomic Categories
The chapter further introduces the concept of taxonomic categories, providing a hierarchical framework for classifying and organizing living organisms based on their evolutionary relationships. These categories include species, genus, family, order, class, phylum, and kingdom.
- 1.3.1 Species
- 1.3.2 Genus
- 1.3.3 Family
- 1.3.4 Order
- 1.3.5 Class
- 1.3.6 Phylum
- 1.3.7 Kingdom
1.4 Taxonomical Aids
Finally, section 1.4 explores various taxonomical aids that assist scientists in the classification and study of living organisms. These aids include:
- 1.4.1 Herbarium
- 1.4.2 Botanical Garden
- 1.4.3 Museum
- 1.4.4 Zoological Parks
- 1.4.5 Key
Through the utilization of these aids, researchers can better understand the intricacies of the living world and unravel its mysteries.
Topic Explanation
Chapter Extract
Points to Remember
2.Life is a complex organisation expressing itself through chemical reactions and exhibit characteristics of living organisms.
3.Characteristics of Living Organisms : Growth, reproduction, metabolism,
cellular organisation, consciousness (ability to sense environment), selfreplicating and self regulation.
🟢 Reproduction and growth are NOT deining properties.
🟢 Metabolism, cellular organisation and consciousness are deining properties.
🟢 Living organisms are self-replicating, evolving, self-regulating and interactive systems capable of responding to external stimuli.
4.Biodiversity : Term used to refer to the variety of microorganisms, plant and animals on earth.
5. Need for classiication : To organise the vast number of microorganisms,
plants and animals into categories that could be named, remembered, studied and understood.
6.Three Domains of Life : Proposed by Carl Woese in 1990 who also proposed the six kingdom classiication for living organisms. The three Domains of life are Archaea, Bacteria and Eukarya.
Domains of life
1 Archaea
1.1 Kingdom Archaebacteria
2 Bacteria
2.1 Eubacteria
3 Eukarya
3.1 Protista
3.2 Fungi
3.3 Plantae
3.4 Animalia
7.Taxonomy : Study of principles and procedures of identiication, nomenclature and classiication.
8.Systematics : It deals with classiication of organisms based on their diversities and relationships among them. Term was proposed by Carolus Linnaeus who wrote ‘Systema Naturae’.
9.Concept of Species : All the members that can interbreed among themselves and can produce fertile offsprings are the members of same species. This is the biological concept of species proposed by Mayr.
10.Taxa : Each category (i.e., unit) of classiication is called as a taxon.
11.Taxonomic Hierarchy : Classiication of organisms in a defnite sequence of taxon or category or rank in a desending order.
Kingdom → Phylum /Division → Class → Order → Family → Genus → Species.
12.Binomial Nomenclature : Given by Carolus Linnaeus. Each scientiic name has two components-Generic name + Speciic epithet.
13.ICBN : International Code for Botanical Nomenclature (for giving scientiic name to plants.)
14.ICZN : International Code of Zoological Nomenclature (for giving scientiic name to animals.)
15.Rule for Nomenclature :
🟢 Latinised names are used.
🟢 First word is genus, second word is species name.
🟢 Printed in italics; if handwritten then underlined separately.
🟢 First word starts with capital letter while species name written in small letter.
16. Scientiic names of some organisms :
Man — Homo sapiens
Housely — Musca domestica
Mango — Mangifera indica
Wheat — Triticum aestivum
17.Taxonomical Aids are the tools for study of taxonomy.
18.Museums in educational institutes (school and colleges) have collection of skeletons of animals, stuffed and preserved specimens of organisms for study and reference.
19.Zoological Parks (Places where wild animals are kept in protected environment under human care) Example : National Zoological Park, Delhi.
20.Herbarium : Store house of dried, pressed and preserved plant specimen on sheets, kept systematically according to a widely accepted system of classiication, for future use.
21.Botanical Garden : Collection of living plants for reference.
Example : Royal Batanical garden Kew (England), National Botanical Research Institute (Lucknow), Indian Botanical Garden Howrah.
22.Keys : (Used for indentiication of plants and animals on the basis of similarities and dissimilarities.)
23.Couplet : are the two alternate characteristic statement used in key to identify organisation.
24.Each Statement of the key is called a lead.
25. 🟢 Flora (Index to plant species found in a particular area.
26. 🟢 Manuals (Provide information for identiication of name of species in an area.)
27. 🟢 Mongoraphs (Contain information on any one taxon.)
Special Notes by Shastri Ji
Flash Cards
Memory Maps
Question and Answer from NCERT Books
Previous Year Question Answer
Comprehensive MCQ Test
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