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Biology · Class 12 Science

Bihar Bseb Class 12 Biology — Real Previous-Year Papers

with complete answers

Real previous-year board papers, year by year — the official exam pattern, the full question paper, and every question solved the concept-first way. Distinct from the chapter-wise textbook bank.

2018–2026
Years of papers
8
Total Papers
8
Real Board Papers
0
Sample papers
688
Real-paper Q & A
0
Sample-paper Q & A

Real board-paper questions available, by year

96 Q2026complete
96 Q2025complete
96 Q2024complete
96 Q2023complete
96 Q2022complete
96 Q2021complete
—2020Not available
59 Q2019complete
53 Q2018complete

Bihar Board Intermediate 2026 · Set A

Real board examination

About this paper

The real Class-12 board examination held in 2026. Every question below is solved the concept-first way. Sample papers are labelled honestly — never shown as a past exam.

Total marks
70
Questions
48
Duration
195 min
Sections
3

The marks / questions / duration above are the official exam pattern. We currently have 96 of this paper’s questions (200% of the full paper), with 96 fully solved. Questions we couldn’t yet extract or verify are held — never shown as complete.

Sections & marks

SectionTypeQuestionsMarks eachTotal
Section A (Objective, Q1–70)Section Section A (Objective, Q1–70)Objective (MCQ) — answer any 35 of 70, on OMR35135
Section B — Short AnswerSection Section B — Short AnswerShort answer — answer any 10 of 2010220
Section B — Long AnswerSection Section B — Long AnswerLong answer (internal choice) — answer any 3 of 63515
Total4870

The question paper

The questions we hold for this paper, laid out by section. Solutions are on the Answers tab.

Board Examination

Biology

Bihar Board Intermediate 2026 · Set A

Series/Set: ARoll No. ________
Time Allowed: 3 hr 15 minMaximum Marks: 70

General Instructions

  1. This question paper contains 48 questions divided into 3 sections — Section A (Objective, Q1–70), Section B — Short Answer, Section B — Long Answer.
  2. Section Section A (Objective, Q1–70) comprises 35 questions of 1 mark each (Objective (MCQ) — answer any 35 of 70, on OMR).
  3. Section Section B — Short Answer comprises 10 questions of 2 marks each (Short answer — answer any 10 of 20).
  4. Section Section B — Long Answer comprises 3 questions of 5 marks each (Long answer (internal choice) — answer any 3 of 6).

Above is the official exam pattern. The questions printed below are those we currently hold for this paper.

Section A

Q1.
If a person's blood group is AB, what would be his / her genotype?
  • (a) I^A i
  • (b) I^B i
  • (c) ii
  • (d) I^A I^B
[1]
Q2.
How many types of gametes would be formed if the genotype of plant is AaBbCc?
  • (a) Two
  • (b) Four
  • (c) Eight
  • (d) Sixteen
[1]
Q3.
Which of the following is not a chromosomal disorder?
  • (a) Klinefelter's syndrome
  • (b) Turner's syndrome
  • (c) Down's syndrome
  • (d) Haemophilia
[1]
Q4.
In which of the following animals does sex determination depend on number of chromosome sets?
  • (a) Birds
  • (b) Honeybees
  • (c) Grasshoppers
  • (d) Mammals
[1]
Q5.
Which of the following laws is based on monohybrid cross?
  • (a) Law of dominance
  • (b) Law of segregation
  • (c) Law of independent assortment
  • (d) Both (A) and (B)
[1]
Q6.
Fossils are found in which type of rocks?
  • (a) Sedimentary rock
  • (b) Metamorphic rock
  • (c) Igneous rock
  • (d) All of these
[1]
Q7.
Which of the following are examples of homologous organs in animals?
  • (a) Eyes of octopus and human
  • (b) Sweet potato and potato
  • (c) Flippers of penguins and dolphins
  • (d) Heart of reptiles and mammals
[1]
Page 1 of 11
Q8.
Which of the following was more like ape? (a) Dryopithecus (b) Ramapithecus (c) Homo erectus (d) Australopithecus
[1]
Q9.
Which of the following enzymes causes lactose to enter the bacterial cell? (a) Beta galactosidase (b) Permease (c) Transacetylase (d) Lactase
[1]
Q10.
Who stated that in double stranded DNA sum of purine nitrogenous bases is equal to the sum of pyrimidine nitrogenous bases? (a) Miescher (b) Watson and Crick (c) Wilkins (d) Chargaff
[1]
Q11.
A typical nucleosome is composed of (a) 200 base pairs of DNA (b) Histone octamer (c) Both (A) and (B) (d) Acidic protein
[1]
Q12.
What did Hershey and Chase conclude on the basis of their experiments? (a) Protein from the virus enters the bacteria (b) DNA from the virus enters the bacteria (c) RNA from the virus enters the bacteria (d) Transforming principle
[1]
Q13.
What is the process of removal of introns and mutual joining of exons called? (a) Splicing (b) Tailing (c) Capping (d) Transcription
[1]
Q14.
Which of the following statements is incorrect about the genetic code? (a) The codon is triplet (b) It is unambiguous and specific (c) It is degenerate (d) All 64 codons code for amino acids
[1]
Q15.
How many mega-biodiversity countries are there in the world? (a) 25 (b) 34 (c) 14 (d) 17
[1]
Q16.
Which region got comparatively shorter span of time for species evolution and diversification due to frequent glaciation? (a) temperate region (b) tropical region (c) polar region (d) glaciation occurred in all regions
[1]
Q17.
Which is called the lungs of the earth? (a) Forest (b) Temperate region (c) Amazon rainforest (d) Tropical Savannah
[1]
Page 2 of 11
Q18.
Which of the following species became extinct due to over-exploitation? (a) Passenger pigeon (b) Giant Panda (c) Nile Perch (d) 200 species of cichlid fish
[1]
Q19.
Deriving countless direct economic benefits from nature by humans is ........ argument for conservation of biodiversity. (a) narrowly utilitarian (b) broadly utilitarian (c) ethical (d) all of these
[1]
Q20.
Which of the following is not the primary consumer of an ecosystem? (a) Zooplankton (b) Cow (c) Grasshopper (d) Wolf
[1]
Q21.
How much percentage of photo-synthetically active radiation is captured by plants? (a) 50% (b) 2-10% (c) 10% (d) 20%
[1]
Q22.
What is the raw material for decomposition called? (a) Humus (b) Inorganic substance (c) Detritus (d) Organic substance
[1]
Q23.
What is secondary consumer called? (a) Herbivores (b) Primary carnivores (c) Secondary carnivores (d) Consumers
[1]
Q24.
What are those called which obtain energy and nutrition from breaking dead organic matter or detritus? (a) Saprotrophs (b) Heterotrophs (c) Detritivores (d) Parasite
[1]
Q25.
Which of the following is the pollinating agent of Ophrys? (a) Wasp (b) Humming bird (c) A species of bee (d) Bat
[1]
Q26.
Which of the following processes decreases population density? (a) Immigration (b) Death (c) Emigration (d) Both (B) and (C)
[1]
Q27.
Which of the following was used to control the cactus that had been introduced in Australia? (a) Moth (b) Calotropis (c) Phytophagous insects (d) Virus
[1]
Q28.
What is lichen an example of? (a) Mutualism (b) Competition (c) Parasitism (d) Commensalism
[1]
Page 3 of 11
Q29.
Which of the following is one of the most resistant organic materials? (a) Pectin (b) Cellulose (c) Sporopollenin (d) Chitin
[1]
Q30.
Which of the following cells is present in pollen grain of angiospermic plants? (a) Vegetative cell (b) Generative cell (c) Antipodal cell (d) Both (A) and (B)
[1]
Q31.
In which of the following seeds is perisperm not found? (a) Beet (b) Black pepper (c) Wheat (d) Both (A) and (B)
[1]
Q32.
Which of the following seeds has more than one embryo? (a) Citrus (b) Mango (c) Orange (d) All of these
[1]
Q33.
What is cotyledon called in grass family? (a) Plumule (b) Radicle (c) Hypocotyl (d) Scutellum
[1]
Q34.
Which cell of the embryo sac becomes primary endosperm cell after triple fusion? (a) Central cell (b) Synergids (c) Antipodals (d) Egg cell
[1]
Q35.
Which of the following plays an important role in guiding the pollen tube into the synergids? (a) Antipodals (b) Filiform apparatus (c) Central cell (d) Micropyle
[1]
Q36.
Which of the following cells are found in seminiferous tubules? (a) Sertoli cells (b) Interstitial cells (c) Spermatogonia (d) Both (A) and (C)
[1]
Q37.
After how many months of pregnancy does the limbs and digits of foetus develop? (a) One month (b) Two months (c) Three months (d) Six months
[1]
Q38.
Which of the following placental hormones is produced during pregnancy? (a) hCG (b) hPL (c) relaxin (d) all of these
[1]
Q39.
In which structure of sperm are the enzymes present which help in fertilisation of the ovum? (a) Middle piece (b) Neck (c) Nucleus (d) Acrosome
[1]
Page 4 of 11
Q40.
Which of the following cells is haploid? (a) Oogonia (b) Primary oocyte (c) Secondary oocyte (d) All of these
[1]
Q41.
What is the main role of large amount of progesterone secreted by corpus luteum? (a) maintenance of endometrium of uterus (b) maintenance of perimetrium of uterus (c) maintenance of myometrium of uterus (d) None of these
[1]
Q42.
What is it called when an embryo having more than eight blastomeres is transferred to the uterus for development? (a) IVF (b) Intrauterine Transfer (c) Zygote Intra-fallopian Transfer (d) ICSI
[1]
Q43.
Which of the following is/are responsible for pneumonia in humans? (a) Streptococcus pneumoniae (b) Salmonella (c) Haemophilus influenzae (d) Both (A) and (C)
[1]
Q44.
What type of organism is the pathogen responsible for malaria? (a) Virus (b) Bacteria (c) Protozoa (d) Nematode
[1]
Q45.
Which of the following diseases is/are transmitted by insect vectors? (a) Typhoid (b) Malaria (c) Filaria (d) Both (B) and (C)
[1]
Q46.
What kind of barrier is the interferon secreted by virus infected cells? (a) Cytokine barrier (b) Physical barrier (c) Cellular barrier (d) Physiological barrier
[1]
Q47.
Which of the following cells are responsible for humoral immune response? (a) B-lymphocytes (b) T-lymphocytes (c) Killer lymphocytes (d) Macrophages
[1]
Q48.
What is taken by the patient to stop graft rejection? (a) Immunosuppressant (b) Vaccine (c) To introduce readymade antibodies in the body (d) All of these
[1]
Q49.
Which of the following are primary lymphoid organs? (a) Bone marrow and tonsils (b) Bone narrow and thymus (c) Lymph nodes (d) Thymus and lymph nodes
[1]
Page 5 of 11
Q50.
Which of the following viruses has reverse transcriptase enzyme? (a) TMV (b) Bacteriophage (c) HIV (d) All of these
[1]
Q51.
Which of the following drugs interferes with transport of dopamine? (a) Nicotine (b) Hashish (c) Morphine (d) Cocaine
[1]
Q52.
Which vitamin content increases due to conversion of milk into curd? (a) Vitamin A (b) Vitamin B2 (c) Vitamin C (d) Vitamin B12
[1]
Q53.
Which of the following is the blood cholesterol lowering agent? (a) Statin (b) Cyclosporin-A (c) Antibiotic (d) Streptokinase
[1]
Q54.
Which of the following pairs is incorrect? (a) Cyclosporin-A – Produced by fungus (b) Statin – Produced by yeast (c) Streptokinase – Produced by bacteria (d) Butyric acid – Produced by fungus
[1]
Q55.
Which of the following cyanobacteria fixes atmospheric nitrogen? (a) Nostoc (b) Anabaena (c) Oscillatoria (d) All of these
[1]
Q56.
With the help of what are butterfly caterpillars controlled? (a) Pseudomonas (b) Trichoderma (c) Bacillus thuringiensis (d) Baculovirus
[1]
Q57.
Who of the following scientists observed that restriction endonuclease can cut DNA strands in a particular shape? (a) Herbert Boyer (b) Stanley Cohen (c) Watson (d) Crick
[1]
Q58.
Cutting DNA at a specific site is made possible by which enzyme? (a) Restriction endonuclease (b) Alkaline phosphatase (c) DNA ligase (d) Nuclease
[1]
Q59.
In which of the following is the large volume of culture processed to produce appreciable quantities of products? (a) Distillation unit (b) Bioreactor (c) PCR (d) Electrophoresis unit
[1]
Page 6 of 11
Q60.
The base pillar of both strands of DNA double helix is made of (a) Sugar - Phosphate (b) Sugar - Nitrogenous base (c) Nitrogenous base - Phosphate (d) Sugar-Phosphate-Nitrogenous base
[1]
Q61.
What is essential for occurrence of the same kind of sticky ends' of DNA fragments? (a) To cut DNA by the same restriction endonuclease (b) To cut DNA by different restriction endonucleases (c) DNA amplification (d) All of these
[1]
Q62.
During gel electrophoresis, fragments of DNA move towards which electrode? (a) Cathode (b) Anode (c) Towards any electrode depending upon the size of DNA fragment (d) None of these
[1]
Q63.
Which of the following is the sequence from where replication starts in cloning vector? (a) tetR (b) ampR (c) ori (d) more than one
[1]
Q64.
DNA cannot pass through cell membrane because DNA .......... is molecule. (a) hydrophobic (b) hydrophilic (c) amphipathic (d) neutral
[1]
Q65.
Themrostable DNA polymerase used in PCR is isolated from which bacteria? (a) Thermus aquaticus (b) E. coli (c) Salmonella (d) Eubacteria
[1]
Q66.
Why does Bt toxin protein not kill the Bacillus? (a) Bt toxin protein exists as inactive protoxins (b) Bt toxin protein is converted into harmless form by Bacillus (c) One enzyme of Bacillus inactivates Bt toxin protein (d) All of these
[1]
Q67.
Which technique was used to prevent infection of tobacco plants from Meloidegyne incognitia tapeworm? (a) RNA interference (b) Cry protein (c) Somatic hybridisation (d) Pesticide
[1]
Q68.
Gene therapy was first used to remove the deficiency of which of the following enzymes? (a) DNA polymerase (b) Uracil DNA glycosylase (c) Adenosine deaminase (d) Beta galactosidase
[1]
Page 7 of 11
Q69.
In 1997 an American company got the patent rights for a new variety of Basmati developed by hybridizing Indian Basmati rice with which variety of rice? (a) IR-36 (b) Pusa 1121 (c) Semi-dwarf variety of rice (d) Indica rice
[1]
Q70.
Which human protein is found in milk of the first transgenic cow-Rosie? (a) Alpha-1 antitrypsin (b) Alpha lactalbumin (c) Albumin (d) p53
[1]
Section B

Q1.
What is autogamy? What adaptations are there in flower for it?
[2]
Q2.
What is emasculation?
[2]
Q3.
Draw well labelled diagram of sperm.
[2]
Q4.
Name male accessory glands with their roles.
[2]
Q5.
What are sex-chromosomes and autosomes?
[2]
Q6.
What is Turner's syndrome?
[2]
Page 8 of 11
Q7.
Write four salient features of Human Genome Project.
[2]
Q8.
What is the example of divergent evolution?
[2]
Q9.
What is the use of Widal test?
[2]
Q10.
What are cellular barriers in innate immunity?
[2]
Q11.
What is clot bluster? What is its source?
[2]
Q12.
What are cannabinoids?
[2]
Q13.
Define recognition sequence.
[2]
Q14.
Define transformation.
[2]
Q15.
What is RNA interference?
[2]
Page 9 of 11
Q16.
What is explant?
[2]
Q17.
Write three advantages of predation.
[2]
Q18.
What is humus and what effect does it have on soil?
[2]
Q19.
What is latitudinal gradient in biodiversity?
[2]
Q20.
What do you mean by the Evil Quartet'?
[2]
Section C

Q1.
Compare endosperm and perisperm. Describe the development of endosperm.
[5]
Q2.
Write short notes on any two of the following : (a) Intra-uterine devices (b) Structure of testis (c) Incomplete dominance.
[5]
Page 10 of 11
Q3.
Write short notes on any two of the following : (a) Chromosomal theory of inheritance (b) Nucleosome (c) Transfer RNA
[5]
Q4.
Describe sewage treatment.
[5]
Q5.
Explain various components of ecosystem.
[5]
Q6.
Describe in brief the features of cloning vector.
[5]
Page 11 of 11