🧬 Class 12 Biology Model Paper 2026
(Based on Latest CBSE Exam Pattern)
Time: 3 Hours
📘 Introduction
This Class 12 Biology Model Paper 2026 is specially designed according to the latest CBSE board exam pattern. The question paper covers all important units, follows proper section-wise marking, and includes competency-based, short answer, and long answer questions. Practicing this model paper will help students understand the real exam format, improve time management, and boost confidence before the final board examination.
📌 General Instructions
- All questions are compulsory.
- The question paper consists of 5 Sections – A, B, C, D, and E.
- Use of diagrams is recommended wherever necessary.
- Write neat and labeled diagrams.
- Section-wise marks are indicated against each question.
Class 12 Biology Model Paper 2026
Class 12 Biology Model Paper 2026 PDF | CBSE Biology Sample Question Paper
🔹 Section A – Multiple Choice Questions (Objective)
(1 × 50 = 50 Marks)
- The enzyme responsible for joining Okazaki fragments is:
a) DNA polymerase
b) DNA ligase
c) RNA primase
d) Helicase - The connecting link between living and non-living is:
a) Bacteria
b) Virus
c) Algae
d) Fungi - Which hormone regulates blood glucose level?
a) Thyroxine
b) Insulin
c) Adrenaline
d) Estrogen - Site of fertilization in humans is:
a) Ovary
b) Uterus
c) Fallopian tube
d) Cervix - Bt cotton is resistant to:
a) Viral infection
b) Bacterial disease
c) Insect pests
d) Fungal disease - Plasmids are used as:
a) Enzymes
b) Hormones
c) Vectors
d) Antigens - The causative agent of AIDS is:
a) Bacteria
b) Fungus
c) Protozoa
d) Virus - Which of the following is an STD?
a) Typhoid
b) Gonorrhoea
c) Cholera
d) Malaria - The first step of DNA replication is:
a) Elongation
b) Transcription
c) Unwinding
d) Translation - The study of cancer is known as:
a) Immunology
b) Oncology
c) Pathology
d) Neurology - Which gas is responsible for greenhouse effect?
a) Oxygen
b) Nitrogen
c) Carbon dioxide
d) Hydrogen - The pollen grain develops in:
a) Ovule
b) Anther
c) Ovary
d) Stigma - Which enzyme cuts DNA at specific sites?
a) Ligase
b) Polymerase
c) Restriction enzyme
d) Helicase - Crossing over occurs during:
a) Prophase I
b) Metaphase I
c) Anaphase I
d) Telophase I - The number of chromosomes in human gametes is:
a) 23
b) 46
c) 22
d) 44 - Which hormone is secreted by adrenal gland?
a) Insulin
b) Thyroxine
c) Adrenaline
d) Progesterone - The process of formation of gametes is called:
a) Fertilization
b) Meiosis
c) Mitosis
d) Cleavage - Which of the following is biodegradable?
a) Plastic
b) Glass
c) Sewage
d) DDT - The vector used in genetic engineering is:
a) Virus only
b) Bacteria only
c) Plasmid
d) Enzyme - Which disease is caused by Plasmodium?
a) Dengue
b) Malaria
c) Typhoid
d) Tuberculosis - The site of photosynthesis in plants is:
a) Mitochondria
b) Chloroplast
c) Ribosome
d) Nucleus - Which part of the brain controls balance?
a) Cerebrum
b) Medulla
c) Cerebellum
d) Pons - Gene therapy is used to treat:
Class 12 Biology Model Paper 2026 a) Genetic disorders
b) Viral fever
c) Cancer only
d) Bacterial diseases - Which organ produces bile?
a) Pancreas
b) Liver
c) Gall bladder
d) Kidney - RNA differs from DNA because it contains:
a) Thymine
b) Ribose sugar
c) Deoxyribose
d) Double strand - Which vitamin is synthesized in skin?
a) Vitamin A
b) Vitamin B
c) Vitamin C
d) Vitamin D - The male reproductive hormone is:
a) Estrogen
b) Progesterone
c) Testosterone
d) Oxytocin - Which structure connects mother and fetus?
a) Umbilical cord
b) Placenta
c) Amnion
d) Chorion - The unit of ecosystem is:
a) Species
b) Population
c) Community
d) Biosphere - Which of the following is an air pollutant?
a) Oxygen
b) Nitrogen
c) Sulphur dioxide
d) Argon - The process of protein synthesis is called:
a) Replication
b) Translation
c) Transcription
d) Mutation - The number of heart chambers in humans is:
a) Two
b) Three
c) Four
d) Five - Which disease is caused by bacteria?
a) AIDS
b) Influenza
c) Tuberculosis
d) Dengue - Which blood group is universal donor?
a) A
b) B
c) AB
d) O - The hereditary unit is called:
a) Cell
b) Tissue
c) Gene
d) Chromosome - Which hormone induces ovulation?
a) FSH
b) LH
c) Estrogen
d) Progesterone - Which process causes variation?
a) Mitosis
b) Meiosis
c) Binary fission
d) Fragmentation - The scientific name of human is:
a) Homo sapiens
b) Homo erectus
c) Australopithecus
d) Homo habilis - Which component is absent in virus?
a) DNA/RNA
b) Protein coat
c) Cytoplasm
d) Genetic material - Which is a primary consumer?
a) Grass
b) Deer
c) Lion
d) Fungi - Which part of nephron filters blood?
a) Loop of Henle
b) Collecting duct
c) Bowman’s capsule
d) Ureter - PCR stands for:
a) Protein Chain Reaction
b) Polymerase Chain Reaction
c) Primary Cell Reaction
d) Protein Copy Reaction - Which hormone maintains pregnancy?
a) Estrogen
b) Progesterone
c) FSH
d) LH - Which disease spreads through contaminated water?
a) Malaria
b) Cholera
c) Dengue
d) AIDS - Which kingdom includes unicellular eukaryotes?
a) Monera
b) Protista
c) Fungi
d) Plantae - The largest gland in human body is:
a) Pancreas
b) Liver
c) Thyroid
d) Adrenal - Which organ helps in detoxification?
a) Kidney
b) Liver
c) Lung
d) Heart - Which type of immunity is present at birth?
a) Acquired
b) Adaptive
c) Innate
d) Artificial - Which pollutant causes eutrophication?
a) CO₂
b) Nitrates
c) Oxygen
d) Ozone - The process of loss of water vapour from leaves is:
a) Respiration
b) Transpiration
c) Photosynthesis
d) Guttation
🔹 Section B – Very Short Answer Questions
(2 × 10 = 20 Marks)
- What is gene therapy?
- Name any two sexually transmitted diseases.
- What is genetic drift?
- Define biodiversity.
- What is the role of restriction enzymes?
- Name the causative agent of AIDS.
- What is pollination?
- Write one difference between innate and acquired immunity.
- What is biopiracy?
- Mention any two uses of recombinant DNA technology.
🔹 Section C – Short Answer Questions
(3 × 5 = 15 Marks)
- Explain the process of transcription.
- Describe the structure of a mature sperm.
- What are the causes of biodiversity loss?
- Explain Mendel’s Law of Segregation.
- Write short notes on:
a) Test-tube baby
b) Amniocentesis
🔹 Section D – Long Answer Questions
(5 × 3 = 15 Marks)
- Describe the process of DNA replication with the help of a neat diagram.
- Explain human immunodeficiency virus (HIV), its transmission and prevention.
- What is ecosystem? Explain energy flow and ecological pyramids.
🔹 Section E – Case Study / Competency-Based Questions
(5 × 2 = 10 Marks)
- Case Study – Reproductive Health
Reproductive health means a total well-being in physical, emotional, behavioral, and social aspects of reproduction.
a) What is reproductive health? (1)
b) Name one contraceptive method. (1)
c) What is the role of family planning? (1)
d) Name one government program related to reproductive health. (1)
e) Mention one advantage of small family norm. (1)