NEET Important Chapter - The Living World

This article is created by keeping NEET aspirants in mind.  It contains important notes and questions related to the chapter ‘The Living World’. Also, this article will be a great help for last-minute quick revision as well as for clarifying any concept related to the chapter. 

It covers all the important concepts such as the characteristic features of living beings, rules of binomial nomenclature, and the difference between taxonomy and systematics. These concepts are discussed in a short and crisp way. Along with this, it contains FAQs regarding the NEET exam.

Important Topics of The Living World

• Characteristics of living organisms

• Binomial nomenclature

• Taxonomy Of Biological Classification

• Systematics

• Taxonomical Aids

Important Concepts of The Living World

Characteristics of Living Beings

• Cellular Structure: It is the defining characteristic of all living beings. All the living beings are made up of one or more cells and the cells are made up of living matter which is called living matter.

• Metabolism: The sum total of chemical reactions that occur inside the body of living organisms is called metabolism. It is also the defining characteristic of all living things. 

• Growth: It is an irreversible increase in the mass of an individual. Multicellular organisms increase their mass by cell division. Unicellular organisms also grow through a process of cell division. Cell division is also a means of reproduction in them.

• Reproduction: It is the process of the formation of new individuals of a similar kind. It is not required for a person's survival but it is necessary for the continuation of a population.

• Consciousness: It involves being aware of one's surroundings and reacting to external stimuli. It is the defining characteristic of all living things.

• Organization: The living being is made up of various components that work together to ensure the health of the entire organism.

Terminology

• Systematics: It is the branch of science that deals with the diversity of organisms and all their comparative and evolutionary relationships.

• Taxonomy: It is the branch of science that deals with the principles and procedures of identification, nomenclature and classification of organisms.

• Classification: It is the arrangement of organisms into convenient categories on the basis of their similarities and differences in easily observable and fundamental characters and then the hierarchy of categories is created.

• Nomenclature: It is the science of providing unique names to organisms so that they can be easily recognised and differentiated from others.

• Identification: It is the process of finding the correct name and place of an organism in a system of classification.

Binomial Nomenclature

Carolus Linnaeus developed the binomial nomenclature. It is the system of providing organisms with appropriate and distinct names consisting of two words, the first is genera and the second is species.

Rules of Binomial Nomenclature

• The names are usually written in italics and printed in Latin.

• The genus is represented by the first term, while the species is represented by the second term.

• When the names are handwritten they are separately underlined and when it is printed they are written in italics.

• The genus (first word) starts with a capital letter and the species starts with a small letter. For example; Mangifera indica.

Taxonomic Categories

Hierarchy of categories is the classification of organisms in a definite sequence of categories in descending order from the kingdom and reaching up to species or an ascending order from species to the kingdom is called taxonomic categories.

Hierarchy of Biological Classification

• Species: It is a natural population of individuals which resemble one another in morphological and reproductive characteristics so that they can easily interbreed and produce fertile offspring.

• Genus: It is a group of related species which resemble one another in some characters that are related. For example; Solanum tuberosum (Solanum- genus; tuberosum-species)

• Family: It is the taxonomic category that contains one or more related genera. All the genera of a family show common characters. For example; genera of cats (Felis) and leopard (Panthera) are included in the family Felidae.

• Order: It contains one or more related families. For example; Solanaceae, convolvulaceae, polemoniaceae are placed in the same order polemoniales.

• Class: It contains one or more related orders. For example; Chiroptera, Marsupialia, Rodentia, cetacea, and Carnivora come under the class Mammalia.

• Phylum or Division: The term phylum is used for animals and division for plants. Phylum or division contains one or more classes. For example; Class Mammalia, Aves, Reptilia, Amphibia, Cyclostomata, Chondrichthyes, and Osteichthyes are places in the phylum Chordata.

• Kingdom: It is the topmost taxonomic category. For example; all the animals belong to the kingdom Animalia.

As the hierarchy increases, lesser similar characters are seen. Species show the maximum similar characters while the kingdom shows the minimum.

Taxonomical Aids

The techniques, procedures and stored information that are useful in the identification and classification of organisms are called taxonomic aids.

• Herbarium

It is a place where dried and pressed plant specimens are mounted on sheets and are kept systematically according to a widely accepted system of classification. It is a repository for future use.

• Botanical garden

They are large-sized areas where different types of plants are grown for scientific and educational purposes. Example; Kew (England), Indian Botanical Garden, Howrah (India), National Botanical Research Institute, Lucknow (India).

• Zoological parks

It is commonly known as a zoo. It is the place where different types of living animals are kept in enclosures under human care.

• Museum

It is an institution where preserved materials such as plant or animal species are kept for exhibition, study and reference purposes.

• Key

It is a booklet that contains a list of characters and their alternates which are helpful in the identification of various taxa.

• Catalogue

It is a list that systematically summarises all of the species found in a specific location, generally with a brief description to aid identification.

• Monograph

It is a handbook that contains all information regarding a certain taxon, such as a family or genus.

• Flora

It is a book that contains information about habitat, climate, seasonal changes, distribution, description, and index of plants in certain areas.

• Manual

It's a handbook that details the occurrence, collection, and identification of species present in a specific area.

Difference between Wildlife Sanctuary and National Park

Solved example from Chapter

1. Regeneration is the characteristic feature of living beings. Yes/No.

Ans: Yes, as the organisms that are fragmented regain their lost part of the body. For example; Planaria.

Key point to remember: Regeneration is a type of asexual reproduction.

2. Name the international organization that assigns scientific names to plants.

Ans: The international organization that assigns scientific names to plants is the Botanical Nomenclature International Code (ICBN).

Key point to remember: There are five codes of nomenclature : 

• International Code of Botanical Nomenclature (ICBN)

• International Code of Zoological Nomenclature (ICZN)

• International Code of Bacteriological Nomenclature (IC Bac N)

• International Code of Viral Nomenclature (ICVN)

• International Code of Nomenclature for Cultivated Plants (ICNCP)

Solved Problems from Previous Year Question from the Chapter

1. This aspect is an exclusive characteristic of living things

1. Increase in mass from inside only

2. Perception of events happening in the environment and their memory

3. Isolated metabolic reactions occur in vitro

4. Increase in mass by the accumulation of material both on the surface as well as internally

Ans: (b) Perception of events happening in the environment and their memory.

The ability to perceive and remember events in the environment is the most unique feature of a living thing. Consciousness or irritation are the terms used to describe a living being’s behaviour.

Trick to remember:  Consciousness, Metabolism, and cellular structure are the defining features of living organisms.

2. Biosystematics aims at

1. Delimiting various taxa of organisms and establishing their relationships

2. The classification of organisms based on broad morphological characters

3. The classification of organisms based on their evolutionary history and establishing their phylogeny on the totality of various parameters from all fields of studies

4. Identification and arrangement of organisms on the basis of their cytological characteristics

Ans: (c) The classification of organisms based on their evolutionary history and establishing their phylogeny on the totality of various parameters from all fields of studies

Biosystematics is the study of the past and present diversification of living forms, as well as the links between living entities over time. 

Trick to remember: In biosystematic, evolutionary trees are used to represent relationships.

Practice Questions (The Living World MCQ for NEET)

1. A group of plants and animals with similar features of any rank is

1. Order

2. Family

3. Genus

4. Taxon

Ans: (d) Taxon

It is a population of organisms that represent any level of grouping based on certain and easily observable characteristics.

Key point to remember: Level of grouping is called hierarchy.

2. Which is the correct sequence?

1. Species-Genus-Order-Phylum

2. Kingdom-Phylum-Class-Order

3. Genus-Order-Species-Kingdom

4. Kingdom-Species-Order-Phylum

Ans: (b) Kingdom-Phylum-Class-Order

The given sequence is of taxonomic categories. It is the hierarchy of categories in which organisms are classified in a definite sequence of categories in descending order from the kingdom and reaching up to species or an ascending order from species to kingdom.

Key point to remember: Members of the species show maximum similar characters while the kingdom shows the minimum similar characters.

Conclusion

This article covers all of the important ideas and gives concise explanations of The Living World, making it excellent for NEET applicants who want to revise quickly and effectively. It includes fundamental concepts from Biology NCERT, as well as problems from previous year's NEET exam papers and NEET practice tests. Make sure to put your knowledge to the test by doing the Practice question on your own.