ASSEB Class 12 Biology 2026 - Most Important Questions & Predicted Papers (Based on 2012–2025 Analysis)

Preparing for ASSEB Class 12 Biology 2026 becomes easier when you focus on the most repeated and high-weightage topics. After analyzing previous year question papers from 2012–2025 and the latest syllabus, the following most probable questions and predicted papers are provided for effective exam preparation.

ASSEB Class 12 Biology 2026 - Most Important Questions & Predicted Papers (Based on 2012–2025 Analysis)

Reproduction

Topic	PYQ Frequency	Important Questions for 2026
Sexual reproduction in flowering plants	Very High	Double fertilization and triple fusion; Development of embryo sac; Structure of ovule/flower (diagram); Apomixis & polyembryony
Human reproduction	Very High	Male & female reproductive system; Menstrual cycle; Fertilization & implantation; Gametogenesis
Reproductive health	High	STDs & prevention; Amniocentesis ban; Birth control methods; Assisted reproductive technologies

Genetics & Evolution

Topic	PYQ Frequency	Important Questions for 2026
Mendelian inheritance	Very High	Mendel’s laws; Monohybrid & dihybrid cross; Sex determination; Chromosomal theory
Molecular basis	Very High	DNA as genetic material (Hershey-Chase/Griffith); DNA replication; Transcription & translation; Genetic code; Lac operon; DNA fingerprinting; HGP
Genetic disorders	High	Haemophilia; Down/Turner/Klinefelter; Mutation types
Evolution	Very High	Darwinism; Modern synthetic theory; Hardy-Weinberg principle; Evidences of evolution; Origin of life (Miller)

Biology in Human Welfare

Topic	PYQ Frequency	Important Questions for 2026
Human health & disease	Very High	AIDS (mechanism/prevention); Cancer (causes/detection); Immunity types & barriers; Common diseases (malaria, typhoid, filariasis)
Microbes in welfare	High	Microbes in industry & SCP; Biofertilizers & biopesticides; Sewage treatment; Biogas production

Biotechnology

Topic	PYQ Frequency	Important Questions for 2026
Principles & tools	Very High	Recombinant DNA technology steps; Restriction enzymes; PCR; Gel electrophoresis; Vectors/plasmids
Applications	Very High	Bt crops; Transgenic animals; Genetically engineered insulin; Gene therapy; Ethical issues
Techniques	High	ELISA; Molecular diagnosis; DNA cloning; Gene gun

Ecology

Topic	PYQ Frequency	Important Questions for 2026
Organisms & populations	High	Population growth & interactions; Ecological niche; Adaptations (hydrophytes/xerophytes)
Ecosystem	Very High	Energy flow; Food chain & web; Ecological pyramids; Ecosystem structure; Carbon cycle
Biodiversity & conservation	Very High	Biodiversity importance; Conservation methods; Biodiversity hotspots; Biosphere reserves/Assam parks
Bioresources of Assam	High	Medicinal plants (Neem, Cinchona, Rauwolfia, Tulsi); Timber plants (Teak, Sal, Sissoo, Hollong); Sericulture (Muga, Eri)

Most Expected 2026 Long Questions (5 Marks)

1. Double fertilization with diagram

2. Development of embryo sac / dicot embryo

3. Mendel’s laws / Chromosomal theory

4. DNA as genetic material (Hershey–Chase)

5. Transcription or translation

6. Recombinant DNA technology process

7. Biotechnology in agriculture/medicine

8. Energy flow in ecosystem / ecological pyramids

9. Biodiversity conservation

10. AIDS or Cancer

Most Expected Short Notes (2–3 Marks)

1. Apomixis / Polyembryony

2. Menstrual cycle

3. Amniocentesis ban

4. DNA fingerprinting

5. PCR

6. Biofertilizers

7. SCP

8. Bt crop

9. Immunity barriers

10. Hardy-Weinberg principle

11. Food chain

12. Biosphere reserves of Assam

2026 Biology — 99% Most Probable Questions (Topic-wise Consolidated)

Reproduction

Sexual Reproduction in Flowering Plants

1. Double fertilization and triple fusion

2. Structure of mature embryo sac

3. Development of embryo sac / female gametophyte

4. Development of dicot embryo

5. Apomixis and polyembryony

6. Structure of ovule / flower (labelled)

Human Reproduction

1. Male reproductive system

2. Female reproductive system

3. Gametogenesis (spermatogenesis & oogenesis)

4. Menstrual cycle

5. Fertilization and implantation

6. Pregnancy and parturition

Reproductive Health

• STDs and prevention

• Birth control methods

• Amniocentesis (reason for ban)

• Infertility and ART

Genetics & Evolution

Principles of Inheritance

• Mendel’s laws of inheritance

• Monohybrid & dihybrid cross

• Chromosomal theory of inheritance

• Sex determination in humans

• Linkage and recombination

• Genetic disorders (Haemophilia / Down / Turner)

Molecular Basis of Inheritance

1. DNA as genetic material (Griffith / Hershey-Chase)

2. Structure of DNA

3. DNA replication

4. Transcription

5. Translation

6. Genetic code (features)

7. Lac operon

8. Human Genome Project

9. DNA fingerprinting

Evolution

1. Darwin’s theory of natural selection

2. Modern synthetic theory

3. Hardy-Weinberg principle

4. Evidences of evolution

5. Origin of life (Miller experiment)

6. Adaptive radiation

Biology in Human Welfare

Human Health & Disease

1. AIDS (causative agent, transmission, prevention)

2. Cancer (causes, detection)

3. Immunity (innate vs acquired; barriers)

4. Malaria life cycle

5. Typhoid / Filariasis / Pneumonia symptoms

Microbes in Human Welfare

1. Microbes in industrial products (alcohol, antibiotics)

2. Single Cell Protein (SCP)

3. Biofertilizers

4. Biopesticides (Bt)

5. Sewage treatment

6. Biogas production

Biotechnology

Principles & Processes

1. Recombinant DNA technology (steps)

2. Tools of genetic engineering (enzymes, vectors)

3. PCR technique

4. Gel electrophoresis

5. Plasmid vectors

Applications

1. Bt crops

2. Genetically engineered insulin

3. Gene therapy (ADA)

4. Transgenic animals

5. Molecular diagnosis (ELISA)

6. Ethical issues in biotechnology

Ecology

Organisms & Populations

1. Population growth (exponential/logistic)

2. Population interactions (mutualism, parasitism etc.)

3. Adaptations (xerophytes/hydrophytes)

Ecosystem

1. Ecosystem structure & components

2. Energy flow in ecosystem

3. Food chain & food web

4. Ecological pyramids

5. Carbon cycle

6. Decomposition

Biodiversity & Conservation

1. Biodiversity importance

2. In-situ & ex-situ conservation

3. Biodiversity hotspots

4. Biosphere reserves / National parks of Assam

5. Causes of biodiversity loss

Bioresources of Assam

1. Medicinal plants: Neem, Cinchona, Rauwolfia, Tulsi

2. Timber plants: Teak, Sal, Sissoo, Hollong

3. Sericulture: Muga & Eri silkworm

Highest-Priority 5-Mark Questions (Sure)

1. Double fertilization

2. Mendel’s laws

3. DNA as genetic material

4. Transcription or translation

5. Recombinant DNA technology

6. Biotechnology applications

7. Energy flow / ecological pyramids

8. Biodiversity conservation

9. AIDS / Cancer

10. Malaria life cycle

Highest-Priority 2–3-Mark Questions (Sure)

1. Embryo sac

2. Apomixis

3. Menstrual cycle

4. Amniocentesis

5. DNA fingerprinting

6. PCR

7. Bt crop

8. Biofertilizer

9. SCP

10. Hardy-Weinberg

11. Food chain

12. Biosphere reserve Assam

××××××

ASSEB Class 12 Biology — Predicted Question Paper 2026 (Theory) Set 1

BIOLOGY (Theory)
Full Marks: 70 Pass Marks: 21 Time: Three hours
The figures in the margin indicate full marks for the questions

PART-I (BOTANY) — Marks: 35

1. What is double fertilization? (1)

2. Define apomixis. (1)

3. Name one biofertilizer microbe. (1)

4. What is speciation? (1)

5. Answer the following: (2×4=8)
(a) Write the cells present in a mature embryo sac.
(b) Define fermentation. Name one fermenting microbe.
(c) What are biotic components of ecosystem?
(d) Name one Bt crop and its source organism.

6. Write short notes on (any two): (2×2=4)
(a) Polyembryony
(b) PCR
(c) Ecological pyramid

7. Write the scientific name with utility of the following (any two): (2+2=4)
(a) Neem
(b) Rauwolfia
(c) Teak
(d) Cinchona

8. Describe the development of female gametophyte in angiosperms. (3)
OR
Explain Hardy-Weinberg principle. (3)

9. Write briefly on recombinant DNA technology. (3)
OR
Explain energy flow in ecosystem. (3)

10. Write an account on biotechnological applications in agriculture. (4)
OR
Write briefly on modern synthetic theory of evolution. (4)

11. Describe double fertilization in angiosperms with diagram. (5)
OR
Describe ecological pyramids with diagram. (5)

PART-II (ZOOLOGY) — Marks: 35

1. Fill in the blanks (any two): (1×2=2)
(a) AIDS is caused by ______ virus.
(b) The genetic material is ______.
(c) Ovulation is induced by ______ hormone.
(d) The infective stage of malarial parasite is ______.

2. Answer any two: (1×2=2)
(a) What is DNA fingerprinting?
(b) Define immunity.
(c) What is menopause?
(d) What is transgenic animal?

3. Answer any four: (2×4=8)
(a) State Mendel’s laws of inheritance.
(b) Write the symptoms of cancer.
(c) What are barriers of innate immunity?
(d) Write briefly on malaria.
(e) Define gene mutation with example.
(f) What is assisted reproductive technology?

4. Write the differences between (any two): (2×2=4)
(a) Spermatogenesis and oogenesis
(b) Active and passive immunity
(c) Linkage and recombination
(d) DNA and RNA

5. Draw labelled diagram of human sperm. (3)
OR
Draw labelled diagram of DNA double helix. (3)

6. Describe DNA as genetic material with Hershey-Chase experiment. (3)
OR
Write causes and prevention of AIDS. (3)

7. Write the goals of Human Genome Project. (3)
OR
Explain chromosomal theory of inheritance. (3)

8. Describe transcription in detail. (5)
OR
Describe life cycle of malarial parasite. (5)

9. Describe biodiversity conservation and its importance. (5)
OR
Explain cancer causes and detection. (5)

××××××

ASSEB Class 12 Biology — Predicted Question Paper 2026 (Set-2)

BIOLOGY (Theory)
Full Marks: 70 Pass Marks: 21 Time: Three hours
The figures in the margin indicate full marks for the questions

PART-I (BOTANY) — Marks: 35

1. What is polyembryony? (1)

2. Name the enzyme used in PCR. (1)

3. Define biofertilizer. (1)

4. What is adaptive radiation? (1)

5. Answer the following: (2×4=8)
(a) What is triple fusion? Name the nuclei involved.
(b) Define totipotency.
(c) Name two components of ecosystem.
(d) What is Bt toxin?

6. Write short notes on (any two): (2×2=4)
(a) Apomixis
(b) ELISA
(c) Food chain

7. Write the scientific name with utility of the following (any two): (2+2=4)
(a) Tulsi
(b) Sarpagandha
(c) Sal
(d) Coffee

8. Describe the structure of a typical ovule. (3)
OR
Explain Hardy-Weinberg equilibrium. (3)

9. Write briefly on PCR technique and its applications. (3)
OR
Explain ecosystem structure and components. (3)

10. Write an account on biotechnological applications in medicine. (4)
OR
Write briefly on evidences of evolution. (4)

11. Describe development of dicot embryo with diagram. (5)
OR
Describe energy flow in ecosystem with diagram. (5)

PART-II (ZOOLOGY) — Marks: 35

1. Fill in the blanks (any two): (1×2=2)
(a) The father of genetics is ______.
(b) DNA replication is ______.
(c) AIDS affects ______ cells.
(d) The malarial parasite belongs to genus ______.

2. Answer any two: (1×2=2)
(a) What is mutation?
(b) Define STD.
(c) What is genetic code?
(d) What is test cross?

3. Answer any four: (2×4=8)
(a) Explain Mendel’s monohybrid cross.
(b) Write causes of cancer.
(c) What is innate immunity?
(d) Write stages of spermatogenesis.
(e) Define genetic disorder with example.
(f) What is DNA replication?

4. Write differences between (any two): (2×2=4)
(a) Mitosis and meiosis
(b) Transcription and translation
(c) Vaccination and immunization
(d) Homozygous and heterozygous

5. Draw labelled diagram of seminiferous tubule. (3)
OR
Draw labelled diagram of Watson-Crick DNA model. (3)

6. Explain Mendel’s laws of inheritance. (3)
OR
Write symptoms and prevention of malaria. (3)

7. Write salient features of genetic code. (3)
OR
Explain gene therapy with example. (3)

8. Describe translation process. (5)
OR
Describe mechanism of immunity. (5)

9. Describe biodiversity hotspots and conservation methods. (5)
OR
Explain chromosomal disorders with examples. (5)

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COMPLETE NOTES OF CLASS 12 BIOLOGY 

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Chapter No.	Chapter Solutions
1	Sexual Reproduction in Flowering Plants
2	Human Reproduction
3	Reproductive Health
4	Principles of Inheritance and Variation
5	Molecular Basis of Inheritance
6	Evolution
7	Human Health and Diseases
8	Microbes in Human Welfare
9	Biotechnology: Principles and Processes
10	Biotechnology and its Application
11	Organisms and Populations
12	Ecosystems
13	Biodiversity and Conservation: Species
14	Bioresources of Assam

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Class 12 Biology Previous Year Papers (With Solutions)

Year	Question Paper	Solved Paper
2012	View Paper	View Solution
2013	View Paper	View Solution
2014	View Paper	View Solution
2015	View Paper	View Solution
2016	View Paper	View Solution
2017	View Paper	View Solution
2018	View Paper	View Solution
2019	View Paper	View Solution
2020	View Paper	View Solution
2022	View Paper	View Solution
2023	View Paper	View Solution
2024	View Paper	View Solution
2025	View Paper	View Solution

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Disclaimer: These important topics and questions are based on previous year analysis and exam trends. They are meant to support preparation only; no guarantee of marks or success is claimed. Students should study the full syllabus and use this material wisely.