CBSE Class 11 Biology Revision Notes Chapter 1

CBSE Class 11 Biology Revision Notes Chapter 1 – The Living World

Chapter 1 – The Living World – of Class 11 Biology NCERT is an introduction to the many different kinds of species of living things that exist on our planet and how biologists approach studying all these different species by classifying them into different categories. Since this is an introduction to higher-level Biology, Students will need to pay special attention to this chapter in order to comprehend further chapters and score well in their exams.

To help students with their preparation, Extramarks offers CBSE Class 11 Biology Revision Notes for Chapter 1. These notes cover all the important concepts included in the chapter in a concise form so that students can easily revise the chapter before their exams. These notes are easily accessible on the Extramarks’ website.

Access Class 11 Biology Chapter 1 – The Living World

The Notes of Class 11 Biology Chapter 1 can be accessed from the official website of Extramarks. Extramarks is a comprehensive e-learning platform that aims to make studies easier and more enjoyable for students. The notes provided by Extramarks summarise all the important concepts that students need to know so that they can quickly revise their curriculum right before their exams.

1.1 What is Growth

How do you determine what is living and what is not? We all have a general idea of how we separate living from non-living things. Living things reproduce, they grow, they respond to changes in the environment, etc. There are many such characteristics that students will learn in the chapter that help us formally think about what constitutes a living thing.

Growth is one such characteristic that is found to occur in most living organisms. When you were born, you were just an infant with a little body and today you have grown into this full-blown adult. This is growth and all living organisms exhibit this property.

Characteristics of Living Organisms:

The characteristics of a living organism are given below:

1. Growth
2. Metabolism
3. Sensitivity
4. Reproduction
5. Cellular Organisation
6. Movement

1.2 Diversity in the Living World:

There are millions of living organisms in the world that sometimes we cannot even see with our naked eyes. All these living organisms are different and are found in various habitats like forests, oceans, lakes, deserts, etc. Different types of plants, animals, and insects exist, and all are important for balanced survival. Around 1.7 to 1.8 million species have been identified to date. Together, they make up the natural diversity better known as biodiversity.

Binomial Nomenclature:

Carl Linnaeus introduced the binomial nomenclature of plants and animals in the book Species Plantarum in 1753. The biological system of naming organisms is known as the Binomial Nomenclature. In this, the name is made of two terms; the first term indicates the genus, and the second one indicates the species of an organism. For example, Mangifera Indica Linn, where Mangifera is the genus and Indica refers to the same species.

Rules:

• Generally, a scientific name has two components (words) in Latin or is derived from Latin irrespective of their origin.

• The First word of the biological name denotes the genus name whereas the second one denotes species.

• The name of the species is written in italics or underlined separately when handwritten while applying the binomial nomenclature system

• The specific name must start with a small letter while a generic name should start with a capital letter. 

• The name of the author is printed in Roman or an abbreviated form at the end after the species name.

• To each taxonomic group, only one correct name must be assigned.

• The scientific name selected must be short and easy to pronounce.

1.3 Taxonomic Categories:

The term Taxon was introduced in 1956. Mayr in 1964 defined it as the different categories based on various characteristics of an organism that include a taxonomic group of any rank.

Taxonomic Hierarchy:

Taxonomic hierarchies depend upon the common characteristics of various organisms in different categories. It includes characteristics such as kingdom, division of the kingdom, class, order, phylum, family, genus, and species. The hierarchy consists of seven binding categories. They are as follows:

Kingdom – Animalia

↑

Phylum – Chordata

(Division in case of plants)

↑

Class – Mammalia

↑

Order – Primata

↑

Family – Hominidae

↑

Genus – Homo

↑

Species – sapiens

1.4 Taxonomical Aids:

Taxonomical aids are useful for the study of our bioresources and also help in agriculture, forestry, and industry. They are helpful in both laboratories and the field. Herbaria, botanical gardens, museums, and parks are some important taxonomy areas.

1.4.1 Herbarium:

A herbarium is a collection of preserved and labelled plant specimens dried up manually. The plant species are first dried after collection and then pressed and mounted before labelling on the herbarium sheets.

1.4.3 Museum:

The artistic and educational plant or animal species are preserved, stored, and exhibited in museums. There are various museums such as science museums, natural science museums, zoological museums, etc.

Fast Track Revision:

A list of topics that are essential and should be well understood is given below:

1. Living things, their cellular organisation, metabolism, reproduction, development, and other characteristics.
2. Growth and how it occurs in different living organisms
3. Nomenclature, identification of organisms, classification, evolutionary history.
4. Binomial nomenclature and who introduced it, and the naming system
5. The taxonomic arrangement, taxonomic hierarchy, taxon.
6. Taxonomical aids, the procedures, and importance.
7. Herbarium, museum, botanical gardens.
8. Monograph, manual.

Class 11th Biology Subject Importance

Biology is an important branch of science, and the standard of Biology in CBSE Class 11 is quite high. The CBSE Revision Notes on this subject highlight all the crucial topics covered in NCERT chapters. All the concepts are explained extensively and are well researched. Subject matter experts prepare all the study materials included in the notes so that students can prepare more effectively and efficiently.

Importance of Biology Revision Notes

It is not possible to learn and memorise everything included in the textbook. The Biology revision notes are a handy tool that contains important concepts essential for the examinations. The topics included in the notes are written in simple and easy-to-understand language. All these notes can be found on the official website of Extramarks which aims to make learning easier for students.

How are Extramarks Biology Notes Helpful?

1. The CBSE Revision Notes available at Extramarks are authentic and give information about the concepts in a clear and concise form.
2. Professional teachers with ample experience prepare the notes.
3.  Students will come across many important questions that are crucial for the examinations while going through the notes provided by Extramarks.
4. The notes can even assist the students in the preparation for competitive exams such as NEET, PAT, etc.

Introduction to Chapter 1 ( Living World ) of Class 11 Biology

Around 5,94,00,000 living organisms are present in our ecosystem, and each of them possesses different individual features. Chapter 1 of Class 11 Biology deals with the living organisms of the world that are present in our surroundings. It comprises topics about the different characteristics of different species, their traits, and their structure. You can check out the CBSE Class 11 Biology Chapter 1 notes to learn briefly about the chapter.

Topics Covered in Extramarks Notes

The revision notes available with Extramarks cover many essential topics such as the types of organisms present in our surroundings, the types of nutrition they have, their growth structure, metabolic activities they show, the taxonomy rankings, nomenclature, diversity, and many more. All the topics are defined in an expanded form and are written by experts on the subject. You can also check out the CBSE Past Years Question Papers to get an idea about what to expect from this chapter.

Definition of Living

In simple terms, living can be defined as something alive that can grow, move, reproduce, and has sensing ability.

What Do You Mean By The Diversity in The Living World?

Biodiversity is the biological variation of life on earth. It includes various categories of different species living together in a particular habitat. It is an essential feature of the organisms living on earth.

What are the Taxonomic Categories?

Classification involves numerous steps in which each step is represented with a category or rank. This category is the taxonomic category. The taxonomic categories constitute the taxonomic hierarchies.

What are Species?

Species are termed as the class of individual organisms with basic similarities. Species are differentiated through morphological differences.

What Do You Mean By Genus?

A genus, in simple terms, is a group or collection of related living things like plants and animals.

What is Family?

A family is a taxonomic group that contains one or more similar genera. For example, the family Hominidae has monkeys, apes, and humans.

What is an Order?

Order is classified as a higher category, and it is the mass of families that share similar characteristics. You can learn more about it from the revision notes provided by Extramarks.

What is a Class?

Class is another taxonomic group that consists of one or more related orders. For example, Mammalia’s class consists of orders like primata, carnivora, etc.

What is Phylum?

Phylum is a taxonomic rank that lies below the kingdom and above the class. The CBSE Class 11 Biology Chapter 1 notes are useful to study material that gives a deep insight into this topic.

What is Known as the Kingdom?

The kingdom is the second-highest rank in the taxonomic rankings, divided into smaller groups called phyla.