The curriculum of Class 11 Biology begins with a prominent and introductory chapter called The Living World. Being the first chapter of NCERT Biology class 11, it takes you deeper into the uniquely diverse world of varied types of living organisms and aims to impart the scientific understanding of their existence. Apart from the scholastic exams, this chapter is often mentioned in the syllabus of competitive exams like NEET, etc. So to provide you with the key essentials of this topic, this blog presents the living world class 11 notes elucidating the major concepts and questions you must know about.
This Blog Includes:
What is Living?
The first chapter of class 11 Biology begins with a discussion of what living is. It explains ‘Living’ as anything that is capable of growth, development, responsiveness, adaptation, and reproduction is called living. These distinctive characteristics help biology to define something as living.
Characteristics of Living Organisms
As per the living world class 11 chapter, some of the important characteristics or features based upon which we can examine the nature of living are as follows:
Growth and Development
Growth and development can be simply understood as an increase in mass and in the number of individuals. The multicellular organisms increase in mass when cell division occurs, i.e. size, height, and age of the organism increases. However, unicellular organisms grow in number when cell division occurs. While the growth happens in animals up to a particular time, it is continuous in plants. When an animal or plant is dead, it stops growing. Similarly, cell division in specific tissues occurs for the replacement of lost cells, which is an example of development. Therefore, growth and development is a vital characteristic of a living organism.
In simple words, reproduction is the process of producing progeny, which is similar to or a replica of the parents. It can be sexual or asexual. Reproduction is equivalent to growth, as mentioned in NCERT biology class 11 books, because, in unicellular organisms, the cell division is both growth and reproduction.
According to the Class 11 chapter- The Living World, all organisms are made of chemicals, and organisms use these chemicals to perform various activities. The characteristics of growth and reproduction are the results of this metabolism. There are two types of metabolism, i.e. the destructive aspect catabolism and the constructive aspect anabolism.
Also referred to as responsiveness, consciousness is an essential characteristic used to define the livings. An organism can respond to various environmental stimuli. This way, all the organisms remain aware of their surroundings and keep surviving. The human being is the only species to be aware of the environment and its own body as well.
Diversity in the Living World
The living world comprises millions of plants and animals. There is a large variety of them and other living organisms and is called Biodiversity. Every organism is given a scientific name through the process called Nomenclature. The names are recognized across the globe to avoid any confusion while referring to a species. For example, the scientific name for humans is Homo sapiens. The agreed principle for plants and organisms is provided in the International Code for Botanical Nomenclature (ICBN). On the other hand, the agreed principle for naming the animals is provided in the International Code for Zoological Nomenclature (ICZN).
The next topic in our living world class 11 notes is taxonomic categories. To cover such a huge variety of organisms, they are classified and those with common characteristics are grouped in categories and sections. The process of classification has different steps representing a rank or category, referred to as taxonomic categories. These taxonomic categories together constitute a taxonomic hierarchy. To understand the hierarchy, here are some important pointers from the first chapter of class 11:
- Species: When organisms are grouped based on fundamental similarities, they form a species.
- Genus: A group of related species is called genus. For Example, potato and brinjal belong to the same genera, Solanum but are different species. Two genera have more similarities as compared to two species.
- Family: The group of related genera is called Family. Families are characterized by both vegetative and reproductive features of plant species. In comparison to genera and species, a family has less number of similarities.
- Order: It is a higher category than species, genera, and family. Order is the aggregate of families and shows less number of similar characters.
- Class: The related orders are referred to as a class.
- Phylum/Division: Collection of similar classes with Phylum being used in the case of animals and Division is used in the case of plants.
- Kingdom: It is the highest category of the taxonomic hierarchy. This classification is based on observable features known as Taxon.
Classification and identification are required for the complete and proper study of organisms. For this, biologists, researchers, and scientists require laboratory and field study. As per the living world class 11 notes, some common taxonomical aids are herbarium, museum, botanical garden, botanical garden, and zoological park.
The Living World Class 11 Notes for NEET
- Philosophie Zoologique by Lamarck
- The Origin Of Life by Alexander Oparin
- Principles of Systematic Zoology by Ernst Mayr
- Systema Naturae by Linnaeus
- Philosophia Botanica by Linnaeus
- Species Plantarum by Linnaeus
- Genera Plantarum by Linnaeus
The Living World Class 11 PPT
Given below are some important questions on ‘The Living World’ chapter to brush up your understanding and practice for the exam.
Living’ as anything that is capable of growth, development, responsiveness, adaptation, and reproduction is called living. The characteristics are
Growth and Development
The process of classification is called taxonomy and taxonomic classifications are –
Species: When organisms are grouped based on fundamental similarities, they form a species.
Genus: A group of related species is called a genus. For Example, potato and brinjal belong to the same genera, Solanum but are different species. Two genera have more similarities as compared to the two species.
Family: The group of related genera is called Family. Families are characterized by both vegetative and reproductive features of plant species. In comparison to genera and species, a family has fewer of similarities.
Order: It is a higher category than species, genera, and family. Order is the aggregate of families and shows less number of similar characters.
Class: The related orders are referred to as a class.
Phylum/Division: Collection of similar classes with Phylum being used in the case of animals and Division is used in the case of plants.
Kingdom: It is the highest category of the taxonomic hierarchy. This classification is based on observable features known as Taxon.
The term Taxon refers to a unit of classification and represents a rank.
Biodiversity refers to the variety of living organisms found in a region. Nomenclature is the scientific name for living organisms while Taxonomy is the process of characterisation, identification, nomenclature and classification of organisms.
The process of classification is called taxonomy. The levels of taxonomy are characterisation, identification, classification and nomenclature.
The five biological gardens in India that are used commonly as taxonomical aids are herbarium, museum, botanical garden, botanical garden, and zoological park. These are used by biologists, researchers, and scientists to identify and classify species and organisms.
The universal rules of nomenclature are that all biological names are in Latin and must be in italics. The first word in the name indicates the genus, while the second word denotes its specific epithet.
Key refers to the use of taxonomical aid in the identification of plant and animal species. They help identify similarities and dissimilarities in characters. Each statement in a taxonomic key is referred to as a lead.
Reproduction is the process of producing progeny, which is similar to or a replica of the parents. It can be sexual or asexual. Reproduction is equivalent to growth in unicellular organisms, the cell division is both growth and reproduction.
List of Practice Questions
- Name three botanists who contributed to the field of plant taxonomy.
- Expand ICZN?
- What is a couplet in the taxonomic key?
- Define a monograph.
- Define a metabolism
- The mitotic cell division in amoeba represents growth or reproduction?
- Name a few botanical gardens in India. Also, name the largest botanical garden in the world.
- If a habitat contains 20 animal species and 20 plant species, is it “diversity” or “biodiversity”?
- . Identify the correctly written scientific name for mango species- Mangifera indica/Mangifera Indica.
- What is the lowest category of classification?
- What are the Taxonomic keys?
- Who is known as the Father of Taxonomy?
- What are the 8 levels of taxonomy?
- What is Reproduction?
- What is Biodiversity?
Thus, we hope that through this blog about the living organism class 11 notes, you are now through with this important chapter. For insightful advice regarding your dream career field, reach out to our career experts at LeverageEdu. Hurry Up! Book an e-meeting now!