Biology · Class 12 Science

Odisha Chse 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.

2019–2026
Years of papers: 10
Total Papers: 10
Real Board Papers: 0
Sample papers: 237
Real-paper Q & A: 0
Sample-paper Q & A

Real board-paper questions available, by year

52 Q20262 sets

—2025Paper not available

48 Q20242 sets

42 Q20232 sets

—2022Paper not available

—2021Exam cancelled (COVID-19)

—2020Paper not available

16 Q2019complete

2025 — Paper not available: We publish a CHSE Odisha +2 Science board question paper only after verifying it against a genuine printed original. No such verified paper is available for this year from the sources we check, so we show none rather than an unconfirmed copy.

2022 — Paper not available: We publish a CHSE Odisha +2 Science board question paper only after verifying it against a genuine printed original. No such verified paper is available for this year from the sources we check, so we show none rather than an unconfirmed copy.

2021 — Exam cancelled (COVID-19): The Council of Higher Secondary Education, Odisha (CHSE) cancelled the +2 Science Class-12 board exam for this year statewide due to COVID-19; no annual question paper was ever conducted or printed, so none exists to publish.

2020 — Paper not available: We publish a CHSE Odisha +2 Science board question paper only after verifying it against a genuine printed original. No such verified paper is available for this year from the sources we check, so we show none rather than an unconfirmed copy.

Odisha CHSE +2 Science Board Exam 2026 · Set BOTANY

Real board examination

Sets

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: 35
Questions: 18
Duration: 90 min
Sections: 4

The marks / questions / duration above are the official exam pattern. We currently have 26 of this paper’s questions (144% of the full paper), with 26 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	Objective (MCQ) -- all compulsory, 1 mark each	10	1	10
BSection B	Short notes -- answer any 5 of 8 printed, 2 marks each	5	2	10
CSection C	Differentiate -- answer any 2 of 4 printed, 2.5 marks each	2	2.5	5
DSection D	Long answer -- answer any 2 of 4 printed, 5 marks each	2	5	10
Total		18		35

The question paper

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

Board Examination

Biology

Odisha CHSE +2 Science Board Exam 2026 · Set BOTANY

Series/Set: BOTANYRoll No. ________

Time Allowed: 1 hr 30 minMaximum Marks: 35

General Instructions

This question paper contains 18 questions divided into 4 sections — A, B, C, D.
Section A comprises 10 questions of 1 mark each (Objective (MCQ) -- all compulsory, 1 mark each).
Section B comprises 5 questions of 2 marks each (Short notes -- answer any 5 of 8 printed, 2 marks each).
Section C comprises 2 questions of 2.5 marks each (Differentiate -- answer any 2 of 4 printed, 2.5 marks each).
Section D comprises 2 questions of 5 marks each (Long answer -- answer any 2 of 4 printed, 5 marks each).

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

Section A

Objective (MCQ) -- all compulsory, 1 mark each · 1 mark each · 10 of 10 shown

Q1.

Bacillus thuringiensis has _____ property.

(a) fungicidal
(b) bactericidal
(c) insecticidal
(d) herbicidal

[1]

Q2.

In terms of population interactions, mycorrhiza is an example of _____.

(a) competition
(b) predation
(c) parasitism
(d) mutualism

[1]

Q3.

The genotypic ratio of F2 generation of Mendel's monohybrid cross is _____.

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

[1]

Q4.

An example of contrivance of self-pollination is _____.

(a) cleistogamy
(b) herkogamy
(c) dicliny
(d) heterostyly

[1]

Q5.

A chromosome with centrally located centromere is called _____.

(a) acrocentric
(b) metacentric
(c) telocentric
(d) submetacentric

[1]

Q6.

When more than one codon codes for the same amino acid, the genetic code is called _____.

(a) commaless
(b) universal
(c) degenerate
(d) nonsense

[1]

Q7.

In an ecological pyramid of energy, _____ trophic level is occupied by the herbivores.

(a) first
(b) second
(c) third
(d) fourth

[1]

Page 1 of 4

Q8.

For mass vaccination in India, ___ COVID vaccine, produced successfully by using attenuated corona virus particles, was used. (a) Covishield (b) ZyCoV-D (c) Covaxin (d) Corbevax

[1]

Q9.

In a developing monocot embryo, ___ is often called the scutellum. (a) plumule (b) cotyledon (c) radicle (d) root cap

[1]

Q10.

Genes are made up of ___. (a) protein (b) DNA (c) amino acids (d) nucleosides

[1]

Section B

Short notes -- answer any 5 of 8 printed, 2 marks each · 2 marks each · 8 of 5 shown

Q1.

Write a note on: Split genes.

[2]

Q2.

Write a note on: Nucleotide.

[2]

Q3.

Write a note on: Law of segregation.

[2]

Q4.

Write a note on: Carrying capacity.

[2]

Q5.

Write a note on: Pasteurization.

[2]

Page 2 of 4

Q6.

Write a note on: Golden rice.

[2]

Q7.

Write a note on: Allogamy.

[2]

Q8.

Write a note on: Anemophily.

[2]

Section C

Differentiate -- answer any 2 of 4 printed, 2.5 marks each · 2.5 marks each · 4 of 2 shown

Q1.

Differentiate between Leading strand and Lagging strand.

[3]

Q2.

Differentiate between Genotype and Phenotype.

[3]

Q3.

Cloning vectors.

[3]

Q4.

Significance of fertilization.

[3]

Page 3 of 4

Section D

Long answer -- answer any 2 of 4 printed, 5 marks each · 5 marks each · 4 of 2 shown

Q1.

Explain the chromosomal mechanism of sex determination in man and birds.

[5]

Q2.

Explain Darwin's theory of natural selection.

[5]

Q3.

Give an account of recombinant DNA technology.

[5]

Q4.

Give a brief account of human female reproductive system.

[5]

Page 4 of 4