Biology

CBSE class 12th board examination 2021 will be important for the students as it will play an essential role in their future academics prospects. And you must be aware that only passing in the boards will not suffice as you need to achieve a certain level of marks fixed by the concerned authorities like NTA.

In order to assist students of Biology, who are preparing for the CBSE class 12th board examination 2021, the Biology experts of Anjit Academy have compiled a detailed analysis. Wherein, you will get to know about the important chapters and topics of CBSE class 12th biology board examination 2021.

Reproduction:

As per the NCERT Biology class 12th textbook, the first unit begins with the unit “Reproduction” carrying a weightage of 14 marks. This is the essential aspects of the whole syllabus can be depicted in the following points-

• In the first chapter, the student will study the “Reproduction in Organisms.” Wherein, the meaning of the Terms & examples are important, and fewer questions are expected in the CBSE class 12th board examination 2021 that caries fewer marks.
• In “Sexual Reproduction in Flowering Plants,” important Topics are Development of Male & Female Gametophytes, Out-Breeding Devices, Double Fertilization & Development of Endosperm & Embryo. Herein the question of 1, 2, 3, and 5 marks may be asked in the paper.
• Human Reproduction is the third chapter, according to the NCERT biology class 12th textbook. Here you must focus on the “Male & Female Reproductive System” . You can expect questions carrying a weightage of1, 2, 3, and 5 marks from this chapter.
• In “Reproductive Health” the important questions of CBSE class 12th board exam may be asked from the topic and sub-topics like:-Amniocentesis, Birth Control- Needs and methods, Contraception, as well as Infertility and Assisted reproductive technology. The marking weightage can be of 1, 2, or 3 marks in this chapter that may be asked.

Genetics & Evolution:

The second unit is “Genetics and Evolution” and as per the NCERT biology class 12th textbook, the whole unit carries a total of 18 marks.

• “Principles of Inheritance and Variation” is the fifth chapter in the NCERT biology class 12th textbook. And the important topics according to the boards are “Mendelian inheritance,” “Incomplete dominance,” “Co-dominance,” “Sex determination,” “Mendelian Disorder, and Chromosomal Disorder.” Where you must not skip to learn “Punnett Square Representation is important, as it has more chances of being asked in the paper. In this chapter, you may get questions of 1, 2, 3, or 5 marks in CBSE class 12th board biology paper.
• In the 6th chapter “Molecular Basis of Inheritance” the important topics with respect to the CBSE class 12th board examination 2020 are:- Structure of DNA & RNA, Search for Genetic Material, DNA Replication, Transcription, Translation & Gene Expression and Regulation-Lac Operon, DNA fingerprinting. All the diagrams are very important, and questions carrying 1, 2, 3, or 5 marks can be asked from the important topics of “Molecular Basis of Inheritance.”
• The seventh chapter is “Evolution,” and important topics with respect to the CBSE class 12th biology board examination 2020 are:- Origin of Life, Evidences for Biological Evolution, Modern Synthetic Theory of Evolution, Darwin’s Contribution, Hardy Weinberg’s Principle, Human Evolution. Whereas, you can expect short and low weightage questions of 1, 2, or 3 marks in biology paper of CBSE class 12th board exam.

Biology &  Human Welfare:

The third unit of NCERT biology class 12th textbook is “Biology and Human Welfare,” and has a weightage of 14 marks, including three chapters.

• The unit begins with the 8th chapter of NCERT biology class 12th textbook “Human Health and Diseases,” and the important topics for CBSE board exam 2020 are:- Pathogen Causing Human Diseases, Basic Concepts of Immunology, Cancer, HIV & AIDS, Adolescence- Drug and Alcohol Abuse and can constitute questions of 1, 2, 3, or 5 marks in the board papers.
• The 9th chapter is Strategies for Enhancement in Food Production, and the important topics are:- Inbreeding and outbreeding in animal husbandry, MOET, Plant Breeding-method and usage, Tissue Culture, Somatic Hybridisation, and short questions carrying 1, 2, or 3 can be expected from these.
• Chapter 10 of NCERT biology class 12th textbook is “Microbes in Human Welfare,” which can be considered as one of the easiest and scoring chapters. The important topics are, household food processing, Enzymes, Bio-active molecules & chemicals, Sewage Treatment, Production of Bio-Gas, Bio-control agents, and Bio-fertilizers. And the question of 1, 2, 3, or 5 marks can be framed in the board paper.

Biotechnology & Its Applications:

The fourth unit is “Biotechnology and Its Applications” and carries a weightage of 10 marks. It’s the smallest unit of NCERT biology class 12th textbook and includes only two chapters.

• The first chapter of this unit and the 11th as per the book is “Biotechnology – Principles and Processes.” And the important topics are – Restriction Enzymes, Its nomenclature and working, Gel Electrophoresis, Cloning Vector, Isolation of DNA, and Bio-reactors. The diagrams of this chapter should be considered important in terms of board exams.
• Chapter 12 is “Biotechnology, and its Application” and the important topics are:-Application of Biotechnology in Agriculture, Human Insulin and Vaccine Production, Gene Therapy, Transgenic Animals. You can expect short questions of 1, 2, or 3 marks from the two chapters of this unit.

Ecology & Environment:

Ecology and Environment is the last unit of the NCERT biology class 12th textbook. Interestingly the chapters of this unit are considered as the portion to be mugged up. Whereas the experts of Career Point assert that you will find this unit to be very conceptual if studied in the right way.

• The important topics from the 13th chapter of the textbook “Organisms and Populations” are Population Attributes, Response to a biotic factors, adaptation, population growth, and population Interactions. And 1, 2, 3, or 5 marks questions can be asked from these topics. Additionally, you should pay attention to the diagrams of this chapter as they are important from the exam point of view. And can be asked in the biology paper of CBSE class 12th board examination 2020.
• The important topics of Ecosystem (14th chapter) are – Productivity, Decomposition, Energy Flow, Ecological Pyramids, Ecological Succession, and Nutrient Cycling. And the questions carrying 1, 2, or 3 marks can be framed from these topics. Also, the Diagrams are very important.
• In Biodiversity and its Conservation, which happens to be the 15th chapter of NCERT biology class 12th textbook, the important topics are:- Diversity at all levels, Latitudinal Gradients, Causes of Bio-diversity Losses, Bio-diversity Conservation, and can carry 1, 2, 3, or 5 marks questions in the biology question paper of CBSE class 12th board examination 2020.
• The last and one of the easiest and important chapters with respect to the scoring advantage is “Environmental Issues.” Moreover, the important topics that you must not skip are:- Electrostatic Precipitator, Catalytic Convertor, CNG Better Fuel, Eutrophication, Biomagnifications, Contribution of Ahmed Khan, Green House Effect and Global Warming, Ozone Depletion in the Stratosphere, and Deforestation. 1, 2, 3, or 5 marks questions can be framed from these topics.