Biology NCERT Text Books
NCERT (National Council of Educational Research and Training) has two Biology NCERT text books, one for class 11 & another for class 12. Both text book, each have 5 unit, 22 chapters in class 11 text book and 16 chapters in class 12 text book, cover the 10+2 level higher secondary biology syllabus.
Today I am going to discuss my view about the biological concept behind the order of chapters in two books.
By defination, Biology is the story of ‘Life’ and “Evolution of living organism on earth”.
Unit I : DIVERSITY IN THE LIVING WORLD
1st Chapter of Biology NCERT text book, “The Living World” of this unit explain about life, defination of living organism & diversity of living organism.
The main aim of biology is to scientific study of living organisms which is next to impossible if the indivisual is not identified & classified into its convanient category. Chapter 2nd “Biological Classification” deals about that.
Accroding to R.H Whittaker, an american Ecologist, on the basis of Phylogeny Animal Kingdom comes after Plant Kingdom. Similerly “Plant Kingdom” describe in chapter 3rd, after that in chapter 4th “Animal Kingdom” has described.
Unit II : STRUCTURAL ORGANISATION IN PLANTS AND ANIMALS
Till now the Organism is defined then identified & classifed. To study the organism scientifically we study the organism from external body part to internal.
Firstly we take a Plant as an organism. the external features of a plant body is studied in Morphology which belongs to chapter 5 of Biology NCERT text book : “Morphology of Flowering Plants“.
Internal body part of a plant is to be studied at tissue level in Anatomy which is described in next chapter, chapter number 6 : “Anatomy of Flowering Plants“.
Then we take an Animal as an organism. In chapter 7 “Structural Organisation in Animals“, first Morphology then Anatomy is described of Earthworm (Annelida), Cockroach(Arthopoda) and Frogs(Amphibia) on a evolutionary trends. Basic portion of HISTOLOGY under the topic “Animal Tissue” is illastrated at the beginning of this chapter.
Unit III : CELL : STRUCTURE AND FUNCTIONS
Now we are going into more detail in the body from tissue level to celluler level. In this unit chapter 8 “Cell: The Unit of Life” is about Celluler Structure & Function.
In more depths Celluler composition Biomolecules is explained in the next chapter, chapter number 9 ‘Biomolecules‘.
At the end, Cell cycle and Cell Division : Mitosis, Meiosis goes to chapter 10 of Biology NCERT text book : “Cell Cycle and Cell Division“.
Unit IV : PLANT PHYSIOLOGY
The Physiological activity is occour at Celluler level. So Biology NCERT text book discuss the Physiology after Cell Biology.
At first, Plant Physiology is devided into 5 chapters on the Unit 4th.
Energy is the prime demand of all living organism to be alive which basically come into a organism by food.
Plant as an ecologically Producer (Autoroph) they make their owned food. Plants generally make food on it’s green part mainly leaves. To make food Sunlight, Carbon dioxide and Water is required. Leaves are trapped sunlight easily, Carbon dioxide is also available into air, diffuses to leaf directly. But the problem is arisen for water which comes from soil that is not directly touched with leaves. so a transport system must be required to conduct Water and Minerals from soil to Leaf. That’s why Plant Physiology is started with the chapter 11 of Biology NCERT text book : “Transport in Plants“.
Along with Water, Mineral is also transported from soil which has a vital role in Plant Nutrition. So in next chapter Mineral Element, Nutrient Cycle etc. are described in Chapter 12 : “Mineral Nutrition“.
Now the plant is ready for synthesis its own food (Glucose). the process is caled Photosynthesis. Its come with chapter 13 : “Photosynthesis in Higher Plants“.
Food is now going to each & every cells of the plant body to oxidize for getting Energy. The process of celluler oxidation and release of energy in the form of ‘ATP‘ is called Celluler Respiration which mention in the next chapter, Chapter number 14 “Respiration in Plants“.
Finally, Plant is getting Energy which is to be used in Growth & develpoment of the Plant body. Plant Physiology end with this topic on Chapter no 15 “Plant Growth and Development“.
Unit V : HUMAN PHYSIOLOGY
After Plant Physiology, 7 chapter of Biology NCERT text book is covered for the Human Physiology under 5th unit.
Here we also apply the concept of energy.
Human as an animal is Ecologically Consumer (Heterotroph) means they can not make their own food. So a human body intake ready-made complex food and digest it into a simple form then absorb it. The whole process is explained under chapter 16 “Digestion and Absorption“, first chapter of Human Physiology.
Now Oxygen is required to oxidise the food which is not produce in human body. It come from air, outside the body, inheled by respiratory tract. its cover the chapter 17 : “Breathing and Exchange of Gases“.
But it is impossible to reach the oxygen into all the cells of the body Because Oxygen is transported through respiratory tract only upto Lung. Circulatory system comes into effect which circulate Respiratory gases, Nutrients, Hormone etc. through out the body by Cardio-vasculer system. chapter 18 : “Body Fluied and Circulation“.
During oxidation of foods, Excretory products are also formed, being toxic it should be eliminate from the body. that’s why NCERT illustrated this in the chapter 19 : “Excretory Products and their Elimination“.
Finally energy is relesed from food perticle which is use to be react the physiological stimuli. As an animal, Human body is respond to external stimuli by Movement and Locomotion. Chapter 20 : “Locomotion and Movement” is talking about that.
Human body is consisted by a number of organ and the organ system [e.g; Digestive System, Circulatory System etc.] is cover more than one organ. So a Coordination must be required.
Short-term rapid coordination is established by Nervous system physically. Chapter 21 “Neural Control and Coordination” is explained that Physical Coordination.
Similarly a special type of chemicals called Hormone coordinate and integrate the body part chemically. Human Physiology is completed by this chapter 22 : “Chemical Coordination and Integration“.
Unit VI : REPRODUCTION
An organism is fit for Reproduction when it is mature morphologically, anatomically as well as physiologically. after study all of that we are going to know about Reproduction. Unit 6 of Biology NCERT text book (class 12) is illustrate Reproduction into 4 chapters of Biology NCERT text book.
In the 1st chapter “Reproduction in Organism“, the methods and types of Reproduction is explained, then NCERT goes to specialization for Plants in the chapter 2nd “Sexual Reproduction in Flowering Plants” and for the Human, in the 3rd chapter “Human Reproduction” & 4th chapter “Reproductive Health” is illustrated respectively.
Unit VII : GENETICS AND EVOLUTION
Every species continue their generation through Reproduction, to know the theory of that, unit 7 of Biology NCERT is comes after Reproduction. In this unit, Chapter 5th and 6th is talking about Inheritane and Variation.
The variation may evolve the organism. that’s why Chapter number 7 deal with “Evolution“.
From define the organism to evolution, everything is studied till now, obviously we gain biologycal knowledge which should be applied in Human Walfare. unit 8 and 9 of Biology NCERT give knowledge about that.
Unit VIII : BIOLOGY IN HUMAN WELFARE
In this unit “Human Health and Disease” is discussed in chapter 8th, “Strategies for Enhancements In Food Production” in chapter 9 and “Microbes in Human Welfare” is explained into chapter 10 of class 12th Biology NCERT text book.
Unit IX : BIOTECHNOLOGY
This unit has 2 chapters. Chapter 11 is about Principle and Processes of Biotechnology and its application giives in chapter 12.
Unit X : ECOLOGY
At last, after studied the organism we are going to know about the interaction betwen the organism with its sorrundings. It has 4 Chapters.
Chapter 13 is about “Organisms and Populations“.
Chapter 14 deal with ‘Ecosystem‘.
Chapter 15 is talking about “Biodiversity and Conservation“.
At the end, “Environmental Issue” is explained under chapter 16.
☆ Reference : Biology NCERT Text Book for Class 11th & 12th.