💯 Question Paper for CBSE Class 12 Biology Board Exam 2025-26
Key Advice to Score 70/70:
To really nail the NCERT textbook, go through it one chapter at a time—it’s
basically the go-to guide for CBSE Biology. Make sure to practice all the
important diagrams with clear, labelled drawings, as they can earn you full
marks if you get them right. Also, try solving the last 7-10 years of past year
question papers, CBSE sample papers, pre-boards and question banks
several times. Pay special attention to questions that test your
understanding of how things work, as well as those that involve real-life
examples and diagrams. Try to grasp the concepts thoroughly, rather than
just memorising them—especially when it comes to processes like
replication, transcription, the lac operon, PCR, double fertilisation and
ecological pyramids. When you’re writing your answers, try to organise
them into points with key words, underline important terms and keep an
eye on the time—quick answers in Section A are best, followed by more
detailed answers in Section B. Start by revising the units that are most
important, like Genetics & Evolution (20 marks) and Reproduction (16
marks). Practice full papers in about three hours. This predicted paper is
based on what we’ve seen in the last 7+ years of past year question papers,
repeated questions, CBSE sample papers, pre-boards, half-yearly papers
and question banks. Many questions or very similar ones have a high
chance of appearing (often 80-99% for core topics like the lac operon,
PCR, double fertilisation, the menstrual cycle, Hardy-Weinberg, Bt cotton,
immunity and ecological pyramids).
Unit Weightage (2025-26):
- Reproduction: 16 marks
- Genetics & Evolution: 20 marks
- Biology & Human Welfare: 12 marks
- Biotechnology & Applications: 12 marks
, - Ecology & Environment: 10 marks
Total Theory: 70 marks (Practical: 30 marks).
Exam Pattern (Exact as per 2025-26 SQP):
- 33 questions total, 3 hours.
- Section A: 16 × 1 mark (12 MCQs + 4 Assertion-Reason).
- Section B:5 × 2 marks.
- Section C: 7 × 3 marks.
- Section D: 2 × 4 marks (case-based).
- Section E:3 × 5 marks (long answers).
All questions compulsory; internal choices in some. Draw neat labeled
diagrams wherever required.
99% Sure / Very High-Probability Short Questions (Frequently Repeated in
PYQs, Pre-boards, etc.)
These appear often (or very close variants) and should be prepared
thoroughly for Sections A/B/C:
1-Mark (MCQ/AR/VSA style):
- Unique to angiosperms: Double fertilization / Triple fusion.
- Scutellum in monocot embryo functions as: Cotyledon / Absorptive
organ.
- In lac operon, inducer is: Allolactose / Lactose.
- Taq polymerase source: Thermus aquaticus (heat-stable).
- BOD stands for: Biochemical Oxygen Demand.
Key Advice to Score 70/70:
To really nail the NCERT textbook, go through it one chapter at a time—it’s
basically the go-to guide for CBSE Biology. Make sure to practice all the
important diagrams with clear, labelled drawings, as they can earn you full
marks if you get them right. Also, try solving the last 7-10 years of past year
question papers, CBSE sample papers, pre-boards and question banks
several times. Pay special attention to questions that test your
understanding of how things work, as well as those that involve real-life
examples and diagrams. Try to grasp the concepts thoroughly, rather than
just memorising them—especially when it comes to processes like
replication, transcription, the lac operon, PCR, double fertilisation and
ecological pyramids. When you’re writing your answers, try to organise
them into points with key words, underline important terms and keep an
eye on the time—quick answers in Section A are best, followed by more
detailed answers in Section B. Start by revising the units that are most
important, like Genetics & Evolution (20 marks) and Reproduction (16
marks). Practice full papers in about three hours. This predicted paper is
based on what we’ve seen in the last 7+ years of past year question papers,
repeated questions, CBSE sample papers, pre-boards, half-yearly papers
and question banks. Many questions or very similar ones have a high
chance of appearing (often 80-99% for core topics like the lac operon,
PCR, double fertilisation, the menstrual cycle, Hardy-Weinberg, Bt cotton,
immunity and ecological pyramids).
Unit Weightage (2025-26):
- Reproduction: 16 marks
- Genetics & Evolution: 20 marks
- Biology & Human Welfare: 12 marks
- Biotechnology & Applications: 12 marks
, - Ecology & Environment: 10 marks
Total Theory: 70 marks (Practical: 30 marks).
Exam Pattern (Exact as per 2025-26 SQP):
- 33 questions total, 3 hours.
- Section A: 16 × 1 mark (12 MCQs + 4 Assertion-Reason).
- Section B:5 × 2 marks.
- Section C: 7 × 3 marks.
- Section D: 2 × 4 marks (case-based).
- Section E:3 × 5 marks (long answers).
All questions compulsory; internal choices in some. Draw neat labeled
diagrams wherever required.
99% Sure / Very High-Probability Short Questions (Frequently Repeated in
PYQs, Pre-boards, etc.)
These appear often (or very close variants) and should be prepared
thoroughly for Sections A/B/C:
1-Mark (MCQ/AR/VSA style):
- Unique to angiosperms: Double fertilization / Triple fusion.
- Scutellum in monocot embryo functions as: Cotyledon / Absorptive
organ.
- In lac operon, inducer is: Allolactose / Lactose.
- Taq polymerase source: Thermus aquaticus (heat-stable).
- BOD stands for: Biochemical Oxygen Demand.
