CBSE Class 12 Biology: Marks Allotted To Important Topics, Paper Pattern, Theory And Practicals

For students preparing to get into their dream colleges, the CBSE class 12 board exam serves as a stepping stone. Therefore, students must make the most of every second of this time to effectively prepare for their upcoming boards. Sincere commitment and effort combined with careful planning and focused effort, will help you to complete the well-researched syllabus. An achievable and goal oriented study plan is a must so that you can cover s syllabus in minimum time to score well. How to do it? Do not worry Careers360 is here to help you through these study preps.

Let us look at the topic-wise biology weightage distribution for the board exam. So that you can plan your study accordingly. In the first instalment we will cover weightage distribution for theory and practicals, experiments that may be asked and question paper format. This will help you decide how much time you should spend on a particular unit.

Class 12 (2022-23) - Biology (Theory)

Time: 03 Hours

Max. Marks: 70

Class 12 Biology Practicals

Time allowed: 3 Hours

Max. Marks: 30

*(Credit to a student's work throughout the academic session may be given for a practical record, an investigatory project, a project record, and a viva voce.)

A. List of Experiments

1. To observe pollen germination, prepare a temporary mount.

2. Using the quadrat method, examine the plant population density.

3. Study the plant population frequency using the quadrat method.

4. Prepare a temporary mount of the onion root tip to study mitosis.

5. Isolate DNA from available plant material such as spinach, green pea seeds, papaya, etc.

B. Study and observe the following (Spotting):

1. Flowers adapted to pollination by different agencies (wind, insects, birds).

2. Pollen germination on stigma through a permanent slide or scanning electron micrograph.

3. Identification of stages of gamete development, i.e., T.S. of testis and T.S. of ovary through permanent slides (from grasshopper/mice).

4. Meiosis in onion bud cells or grasshopper testis through permanent slides.

5. T.S. of blastula through permanent slides (Mammalian).

6. Mendelian inheritance using seeds of different colours/sizes of any plant.

7. Prepared pedigree charts of any one of the genetic traits such as rolling of tongue, blood groups, ear lobes, widow's peak and colour blindness.

8. Controlled pollination - emasculation, tagging and bagging.

9. Common disease-causing organisms like Ascaris, Entamoeba, Plasmodium, and any fungus-causing ringworm through permanent slides, models or virtual images or specimens. Comment on symptoms of diseases that they cause.

10. Models specimen showing symbolic association in root modules of leguminous plants, Cuscuta on the host, lichens.

11. Flashcards models showing examples of homologous and analogous organs.

Top Weightage Class 12 Biology Topics

Unit-VII Genetics and Evolution (20 marks)

This unit carries 29 per cent of total theory marks. There are three chapters included in this unit.

Chapter-5: Principles of Inheritance and Variation

Chapter-6: Molecular Basis of Inheritance

Chapter-7: Evolution

Unit-VI Reproduction (16 marks)

This is the second most important unit with 23 per cent of total theory marks. There are three chapters included in this unit.

Chapter-2: Sexual Reproduction in Flowering Plants

Chapter-3: Human Reproduction

Chapter-4: Reproductive Health

These two units together carry more than 50 per cent of weightage. If you are able to cover these units on priority, your half of the work is done. Other units can be focussed on later in this continuation according to the weightage or distribution of marks.

CBSE Class 12 Biology Syllabus 2023: Question Paper Pattern and Format

In order to adequately prepare for their CBSE Class 12 Exam 2023, the students can review the question paper format. Check out the table below:

Note:

• Typology of questions: VSA including MCQs, Assertion – Reasoning type questions; SA; LAI; LA-II; Source-based/ Case-based/ Passage-based/ Integrated assessment questions.

• There would be about a 33 per cent internal choice.

Suggestive verbs for various competencies

1. Demonstrate knowledge and understanding: State, name, list, identify, define, suggest, describe, outline, summarise, etc.

2. Application of Concepts/ Knowledge: calculate, illustrate, adapt, show, explain, distinguish, etc.

3. Analyse, Evaluate and Create: Interpret, analyse, compare, contrast, examine, evaluate, discuss, construct, etc.

CBSE Class 12 Marking Scheme 2023

Each subject on the CBSE Class 12 board exam requires a minimum score of 33 per cent in order to pass. In addition, the candidate must also secure at least 33 per cent aggregate marks to pass the board exam. Candidates who receive aggregate marks of 33 per cent or higher but less than 33 per cent in any subject are required to take the supplementary exam.

CBSE Class 12 Biology Question Paper Design 2023

Every question must be answered. The question paper is divided into five sections: Sections A, B, C, D, and E. There are 33 questions in the question paper.

The class 12 biology syllabus 2022–2023 has been published by the CBSE on their official website, cbseacademics.nic.in.