CBSE Class 12 Biology: Most Important Chapters for High Scores
CBSE 12th 2026 ( CBSE 12th )
Exam On - 17 Feb '26 - 5 Mar '26
Students preparing for the upcoming CBSE class 12 Biology exams can check the most important and scoring chapters for CBSE Class 12 Biology as per the official syllabus. Students should check the Most Scoring Chapters & Topics for CBSE Class 12 Biology Exam and plan their preparation accordingly.
CBSE Class 12 Biology: Most Important Chapters for High Scores
CBSE Class 12 Biology: Most Important Chapters for High Scores: CBSE Class 12 Biology is one of the most scoring subjects for CBSE Class 12 students. Students who study smartly and focus on key chapters can secure desired marks in the CBSE Board class 12 Biology paper. Knowing which chapters carry more weight and which questions are commonly asked can make a big difference while preparation. The CBSE Class 12th Biology paper is out of 70 marks for theory and 30 marks for practicals. Multiple Choice (MCQ), short & long answer type questions are asked in the CBSE Class 12 exams 2026.
To help the students plan better, we have provided the Most Important Chapters for High Scores in the CBSE class 12 Biology exams on this page. It will help them identify which chapters and topics require more attention for the CBSE Class 12th Biology exams.
The Central Board of Secondary Education (CBSE) has already released the CBSE class 12 exam date 2026. As per the announced date, CBSE exams 2026 class 12 will take place between February 17 and April 10, 2026, in pen and paper mode.
- CBSE Class 12 Biology: Most Important Chapters & Topics for High Scores
- Most Important Chapters and Topics in CBSE Class 12 Biology
- Preparation Tips to Score High in CBSE Class 12 Biology
CBSE Class 12 Biology: Most Important Chapters & Topics for High Scores
Students can check the CBSE Board Class 12th Biology chapters/units along with the marks distributed (weightage) for each unit in the table below:
| CBSE Class 12 Biology Topics |
Marks |
|---|---|
| Reproduction |
16 |
| Genetics & Evolution |
20 |
| Biology & Human Welfare |
12 |
| Biotechnology & its Applications |
12 |
| Ecology & Environment |
10 |
| Total |
70 |
Also Read: CBSE Class 12 Biology Question Paper 2025, 2024, 2023, 2022, 2020 PDF Download
Most Important Chapters and Topics in CBSE Class 12 Biology
Students preparing for the CBSE class 12 Biology paper should focus especially on the following chapters/topics:
Reproduction in Organisms & Human Reproduction: Many questions are asked from this unit in the CBSE class 12 Biology exams and are usually easy to score if concepts are clear.
- Sexual Reproduction in Flowering Plants- Topics like pollination, double fertilisation, and embryo development are frequently asked.
- Human Reproduction: Questions about reproductive systems, gametogenesis, and pregnancy are commonly asked in the final exam.
These sections is good for scoring full marks with proper diagram practice.
Genetics and Evolution: This is one of the most high-weightage units in the CBSE class 12 Biology syllabus and often determines overall performance.
- Principles of Inheritance and Variation: Mendel’s laws, chromosomal theory, and genetic disorders are key topics you can’t skip.
- Molecular Basis of Inheritance: DNA structure, replication, transcription, and translation — these topics are rich in marks and often repeated.
- Evolution: Basic mechanisms, Darwin’s theory, and evidences of evolution are frequently asked.
Since this unit carries the highest marks, the students must prepare for it to secure good marks in the final exam.
Biology and Human Welfare: This unit mixes simple theory with real-world examples, making it very scoring.
- Human Health and Disease: Question from the concepts like immunity, diseases, and prevention are asked in the final exam.
- Microbes in Human Welfare: Role of microbes in industries, waste treatment, and farming is commonly tested.
Many questions from this unit are asked as MCQ and short answer.
Biotechnology and its Applications: Biotechnology is a growing area with both theory and application-based questions.
- Biotechnology: Principles and Processes: Understanding tools like PCR, cloning vectors, and restriction enzymes helps you solve both short and long questions.
- Biotechnology and Its Applications: Real-life examples like GM crops and gene therapy often appear in board papers.
Students need to cover and revise this unit for better performance in the final exam.
Ecology and Environment: From this unit, many diagram-based and flowchart based questions are asked.
- Ecosystem: Food chains, pyramids, nutrient cycles — these are common board questions.
- Biodiversity and Conservation / Environmental Issues: Simple concepts like pollution, conservation efforts, and human impact are often repeated.
Preparation Tips to Score High in CBSE Class 12 Biology
Apart from covering the above mentioned key chapters and topics of CBSE class 12 Biology, the students should also follow the below meniotned tips to score good marks in the final CBSE 12th Biology exam:
- Understand concepts deeply: Don’t just memorise terms, try to understand the concepts in the easy way.
- Practice diagrams regularly: Always remember that the neat and labelled drawings earn extra marks in the final exam.
- Practice the Previous Years CBSE Class 12 Biology Question Papers: Solve the CBSE Class 12 Biology sample papers 2026 and past years question papers to know question patterns and frequently asked topics.
- Make short notes and flowcharts: Students must not forget to note down the topics/chapter they have studied especially for big chapters like Genetics and Biotechnology.
With proper planning, the students can prepare for the all the important chapters and topics in CBSE Board Biology exam 2026 class 12.
Also Read: CBSE 12th Preparation Tips 2026: Know Complete Strategy & Guide
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Anything you would want to ask experts?Answered 5 hours ago
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A
Contributor-Level 10
Answered Yesterday
A gap of 1 to 2 years after 12th can be considered normal. Although the students should be able to address it via the valid documents. The reasons like health, finance, skill development or family are accepted.
And if the gap after the high school Diploma is beyond 2 years, strong documentation is r
K
Contributor-Level 9
Answered Yesterday
Yes, it should not be hard for you to get admission to the University of Western Australia as an Indian student with 50% in class 12th. However, please note that it does not put you in the top applicants either. The general admission percentage requirement for international students is 50 to 65%.
Loo
V
Contributor-Level 9
Answered 3 days ago
Top universities require a minimum of 80-90% in your 12th-grade board exams.
- Average universities often accept students with 60-75%.
- For highly competitive courses like Medicine, cut off is usually higher.
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Contributor-Level 7
Answered 3 days ago
Countries like Germany and Norway are excellent options. Because public universities there charge little to no tuition fees. The cost of living and education is significantly lower compared to the USA or UK. You must factor in living expenses and language requirements.
A
Contributor-Level 7
Answered 6 days ago
Class 12 marks are important for fulfilling the admission criteria and tie breaking criteria (if any) during admissions. Admission to Central Universities are conducted through CUET scores, however, candidates must fulfil the minimum marks requirement for admissions.
D
Contributor-Level 6
Answered a week ago
Students must prepare well for the entrance exams such as JEE Main, JEE Advanced, and others. After 12th, the available programmes are BTech, BSc, and others. Students must get 60% to 70% in 12th and good marks in accepted entrance exams for a successful admission to the available programmes.
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Contributor-Level 10
Answered a week ago
Hey, getting into LPU after 12th is pretty straightforward and one of the best choices for a solid college life with great placements and scholarships. Just head to admission.lpu.in, sign up online, and fill out the form for your dream UG course like BTech or BBA—usually need 50-60% in 12th dependin
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Beginner-Level 2
Answered 2 weeks ago
For girls with a Science background after 12th, high-salary courses include Engineering (CS, AI, ECE), Medicine (MBBS, Nursing), Data Science/IT, Pharmacy, Biotechnology, Psychology and Architecture. Fields like Data Science and AI are also emerging fields for girls after 12th science.
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Contributor-Level 8
Answered 3 weeks ago
For admission to RIE courses through the CEE, a minimum of 50% marks in aggregate in your 12th class (or equivalent qualifying examination) is required for general category candidates.
Reserved Categories: A relaxation of 5% is provided, requiring a minimum of 45% aggregate marks for candidates belon
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Contributor-Level 10
Can I do VFX after 12th?