Biology · Class 12 Science

Himachal Hpbose 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: 236
Real-paper Q & A: 0
Sample-paper Q & A

Real board-paper questions available, by year

30 Q2026complete

30 Q2025complete

30 Q2024complete

31 Q2023complete

—2022Not available

31 Q2021complete

28 Q2020complete

28 Q2019complete

28 Q2018complete

HPBOSE Plus Two Board 2026 · Set ANNUAL

Real board examination

This paper has 1 question on a topic removed in CBSE’s 2023-24 syllabus update (each marked Not in syllabus). It’s kept for historical accuracy — the exam really asked it that year — but isn’t in the current syllabus and doesn’t count toward a concept’s importance. Switch to to focus on what’s still examinable.

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: 60
Questions: 30
Duration: 180 min
Sections: 4

The marks / questions / duration above are the official exam pattern. We currently have 30 of this paper’s questions (100% of the full paper), with 30 fully solved. Questions we couldn’t yet extract or verify are held — never shown as complete.

Sections & marks

Section	Type	Questions	Marks each	Total
ASection A	compulsory	12	1	12
BSection B	compulsory	10	2	20
CSection C	compulsory	6	3	18
DSection D	compulsory	2	5	10
Total		30		60

The question paper

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

Board Examination

Biology

HPBOSE Plus Two Board 2026 · Set ANNUAL

Series/Set: ANNUALRoll No. ________

Time Allowed: 3 hoursMaximum Marks: 60

General Instructions

This question paper contains 30 questions divided into 4 sections — A, B, C, D.
Section A comprises 12 questions of 1 mark each (compulsory).
Section B comprises 10 questions of 2 marks each (compulsory).
Section C comprises 6 questions of 3 marks each (compulsory).
Section D comprises 2 questions of 5 marks each (compulsory).

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

Section A

compulsory · 1 mark each · 12 of 12 shown

Q1.

Antibodies are the proteins produced by B-Lymphocytes in response to a pathogen as immunity. Which of the following is responsible for cell mediated immunity?

(a) B - Lymphocytes
(b) T - Lymphocytes
(c) N - K Cells
(d) Phagocytes

[1]

Q2.

What is the role of enzyme Helicase in DNA Replication?

(a) Joining of discontinuously synthesised fragments of DNA.
(b) Unwinding of the double helix of DNA.
(c) Synthesises RNA primer.
(d) Formation of H-bond between complementary base pairs.

[1]

Q3.

Which of the following contraception aids works by releasing hormones to prevent ovulation?

(a) Diaphragm
(b) Oral Contraceptive Pills
(c) Vaults
(d) Copper - T

[1]

Q4.

For a long time, it was believed that the organisms were fixed and unchanging. Which theory was proposed by Charles Darwin to challenge this belief?

(a) Theory of Pangenesis
(b) Theory of Use and Disuse
(c) Theory of Natural Selection
(d) Theory of Inheritance of Acquired Characters

[1]

Q5.

During fertilization, which cell fuses with male gamete to form zygote?

(a) Egg Cell
(b) Polar Cell
(c) Synergid
(d) Antipodal Cell

[1]

Q6.

If a plant has genotype AaBb, what will be the possible number of gametes it may produce?

(a) 1
(b) 2
(c) 3
(d) 4

[1]

Page 1 of 5

Q7.

How many Y-Chromosomes are present in human spermatozoa? (a) 2 (b) 23 (c) 1 (d) 46

[1]

Q8.

Based on the given BOD test results (Sample A-20 mg/L, Sample B-8 mg/L, and Sample C-400 mg/L), which water sample is most likely to be least polluted? (a) Sample A (20 mg/L) (b) Sample C (400 mg/L) (c) Sample B (8 mg/L) (d) Sample A (20 mg/L) and Sample C (400 mg/L) both.

⚠ This question is not in the current syllabus — This question tests Biochemical Oxygen Demand (BOD) as a water-pollution indicator, which was covered in the pre-2023 NC

[1]

Q9.

Name the thermostable enzyme which is required during PCR and is isolated from bacterium Thermus aquaticus. (a) Taq - Polymerase (b) Pfu - Polymerase (c) DNA - Polymerase (d) DNA - Ligase

[1]

Q10.

The diagram given below shows the type of an ecological pyramid. A sharp decrease is seen at higher trophic levels. Choose the correct option for the indication of this pyramid. (a) The energy is increasing at higher trophic level (b) The energy is same in all trophic levels (c) The energy is constant in all trophic levels (d) The energy is decreasing at higher trophic level

[1]

Q11.

Assertion (A): Plants having genes from Bacillus thuringiensis are resistant to insects. Reason (R): The transgenic plants have receptors which convert protoxin into toxin. (a) Both Assertion and Reason are true, and Reason is the correct explanation of Assertion. (b) Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion. (c) Assertion is true but Reason is false. (d) Assertion is false but Reason is true.

[1]

Q12.

Assertion (A): Rhizobium leguminosorum is a symbiotic bacterium found in the root nodules of leguminous plants. Reason (R): This bacterium has the ability to fix atmospheric sulphur into sulphur dioxide. (a) Both Assertion and Reason are true, and Reason is the correct explanation of Assertion. (b) Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion. (c) Assertion is true but Reason is false. (d) Assertion is false but Reason is true.

[1]

Section B

compulsory · 2 marks each · 10 of 10 shown

Q1.

Identify the sex of the organism as male or female in which sex chromosomes are found as below (½×4=2): (i) ZW in birds (ii) XY in human (iii) XX in drosophila (iv) XX in grasshopper

[2]

Q2.

Given below is the diagrammatic view of a mature embryo sac. (i) Name the part A and C (1) (ii) Mention the function of Part E (1)

[2]

Page 2 of 5

Q3.

Some names of diseases and their symptoms are given below in the table. Which out of these is not a correct matching pair? Write the correct symptoms of the particular disease. **OR** Name the yellowish fluid secreted by mother during the initial days of lactation? Why is it essential for newly born infant?

[2]

Q4.

The figure given below is of a plant from which a particular drug is obtained. Based upon the figure answer the following questions: (i) Write the name of the plant. (1) (ii) What is the main property of this plant? (1)

[2]

Q5.

If a marine fish is placed in fresh water aquarium, will the fish be able to survive. Explain with reason. **OR** Given here the interaction of populations of two different species assigning '+' for beneficial interaction, '---' for detrimental interaction and '0' for neutral interaction. Based on these attributes write the names of the interactions between species A and species B.

[2]

Q6.

Cotton worms enjoy feeding on normal cotton plant but killed when feed on Bt cotton plant. Justify the reason.

[2]

Q7.

What are the major causes of species losses in any geographical area?

[2]

Q8.

The figure given below is of clinical method contraception to control pregnancy. Study the figure and answer the following questions. (i) Name the process of the surgical method. (1) (ii) From which part of sex organ a small segment is removed? (1)

[2]

Q9.

Draw a well labeled diagram of the polynucleotide chain of DNA. What are the basic constituents of the polynucleotide chain? (2×1=2)

[2]

Q10.

A patient is suffering from myocardial infarction. Doctor has administered a Clot Buster. Mention the Clot Buster administered and its microbial source.

[2]

Page 3 of 5

Section C

compulsory · 3 marks each · 6 of 6 shown

Q1.

In the past, scientists were not sure about the genetic material of the cell. It was known that some viruses consist solely of DNA and a protein coat. In 1952 Hershey and Chase conducted a series of experiments in this regard. Based on the scenario provided answer the following questions: (i) State the reasons for which Hershey and Chase conducted a series of experiments. (ii) Name the isotopes they had used. (iii) Write the observations they arrived at.

[3]

Q2.

Explain the structure of a mature dicot embryo with the help of a neat and well labeled diagram. **OR** How does double fertilization take place in plants? Enlist the importance of products formed during double fertilization.

[3]

Q3.

The selection of recombinants due to inactivation of antibiotics is a cumbersome procedure. Therefore alternative selectable markers have been developed which differentiate on the basis of colour in presence of chromogenic substrate. (a) Name this process which differentiate recombinant from non-recombinant on the basis of ability to produce colour. (1) (b) Name the enzyme used in this process. (1) (c) Why is inactivation of antibiotics a cumbersome procedure for differentiation of recombinants, hence require alternative. (1)

[3]

Q4.

In 1953, Scientists designed an experiment by recreating the probable conditions of early atmosphere showing chemical evolution. (i) Name these Scientists. (1) (ii) How did they create the same conditions? (1) (iii) What was their finding after conducting this experiment? (1)

[3]

Q5.

Primary productivity is defined as the amount of biomass produced in any unit. The rate of biomass production is called as productivity. It can be divided into Gross Primary Productivity and Net Primary Productivity. How is productivity expressed? Discuss the relationship between Gross Primary Productivity and Net Primary Productivity.

[3]

Page 4 of 5

Q6.

A true cross is made between homozygous dominant inflated green pod (FFGG) and constricted yellow seed (ffgg). (2+1=3) (i) Draw the Punnett Square to represent this cross. (ii) Write the Genotype and Phenotype in F1 generation.

[3]

Section D

compulsory · 5 marks each · 2 of 2 shown

Q1.

The schematic representation of spermatogenesis is given here under. On the basis of the diagram, answer the following questions: (2+3=5) (i) What will be the fate of the egg if it is not fertilized by the sperm. (2) (ii) Explain the different phases of oogenesis. (3) **OR** (i) Draw a well labeled diagram of seminiferous tubules. (2) (ii) What is the function of sertoli cells in spermatogenesis. (2) (iii) Name the hormone which activates the Leydig cells to produce androgens? (1)

[5]

Q2.

(i) Bioreactors are used for large scale production of recombinant products. Enlist the conditions to achieve optimization of bioreactors. (3) (ii) Explain the structure of the most commonly used bioreactor. (2) **OR** (i) Why DNA technology cannot proceed without restriction of endonuclease? (2) (ii) What is the palindromic nucleotide sequence? How is it helpful in rDNA Technology? (2) (iii) Name the technique by which multiple copies of desired DNA or genes are synthesized. (1)

[5]

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