NSEB guide
The Biology Olympiad for Classes 10 to 12, from IAPT’s 2026 brochure and HBCSE’s 2026–27 pages — who can sit NSEB, what the paper looks like, and every stage up to IBO.
- Conducted by
- IAPT (NSEB); HBCSE from INBO onwards
- Academic responsibility
- The Association of Teachers in Biological Sciences (ATBS); IAPT organises the examination
- Classes
- 10, 11 or 12
- Paper
- 60 multiple-choice questions, 216 marks
- Duration
- 2 hours
- 2026 sitting
- Sunday 22 November 2026
What is NSEB?
NSEB, the National Standard Examination in Biology, is the first stage of the Biology Olympiad in India, set at Class 12 level. IAPT conducts it; students who do well sit INBO, conducted by HBCSE.
IAPT describes the National Standard Examinations as the first stage and the only screening tests in India leading to the International Olympiads in their subjects.
Last reviewed 14 September 2026 · Source: iapt.org.in (official document)
Who can sit NSEB?
For NSEB 2026: any student of Class 10, 11 or 12 on 30 November 2026, born 1 July 2007 to 30 June 2012, not having completed (or scheduled to complete) Class 12 boards before 30 November 2026.
IAPT’s NSE 2026 page gives the class rule; the birth-date, passport, residence, board, university, NSEJS and group rules below are from its student brochure, and the OCI note from HBCSE’s 2026–27 brochure.
| Class | Class 10, 11 or 12 on 30 November 2026 |
|---|---|
| Date of birth | Between 1 July 2007 and 30 June 2012, both days inclusive |
| Nationality | Eligible to hold an Indian passport |
| OCI students | Provisionally eligible for every stage up to and including the OCSC, but not for selection to the Indian team, under the Madras High Court orders HBCSE cites |
| Residence | Residing and studying in India, or studying in an Indian school system, since 30 November 2024 or earlier |
| Class 12 board | Must not have completed (or be scheduled to complete) the Class 12 board examination earlier than 30 November 2026 |
| University | Must not have commenced (or be planning to commence) studies at a university or equivalent institution by 1 June 2027 |
| NSEJS | Must not be appearing in NSEJS 2026 |
| Selection groups | Group A: Class XII on 30 November 2026. Group B: Class XI or lower. Selection for the INO is made separately within each group |
Last reviewed 14 September 2026 · Source: iapt.org.in (official document)
What is the NSEB exam pattern?
A two-hour paper of 60 multiple-choice questions for 216 marks: 48 with one correct option, at +3 and −1, and 12 worth 6 marks each with one or more correct options.
| Part | Questions | Marking |
|---|---|---|
| Single correct option | 48 | +3 for the correct choice, −1 for an incorrect choice |
| One or more correct options | 12 | 6 marks each; credit only when every correct option and no incorrect option is marked |
| Total | 60 | 216 marks |
Time: 2:30 pm to 4:30 pm on Sunday 22 November 2026, at the student’s NSE centre.
Language: English, Hindi, Gujarati, Bangla, Kannada, Tamil or Telugu — or another Indian language if 300 students opt for it at registration.
Last reviewed 14 September 2026 · Source: iapt.org.in (official document)
What is the NSEB syllabus?
IAPT’s syllabus sets NSEB and INBO broadly at senior secondary level, up to and including CBSE Class 12 Biology, with Science to Class 10 and Mathematics to Class 12 expected too.
- Diversity of living organisms
- Structural organisation in animals and plants
- Cell: structure and function
- Plant physiology
- Human physiology
- Reproduction
- Genetics and evolution
- Biology and human welfare
- Ecology and environment
Last reviewed 14 September 2026 · Source: iapt.org.in (official document)
What comes after NSEB?
Students selected on their NSEB scores sit INBO, the Indian National Biology Olympiad, conducted by HBCSE. The best from INBO attend a selection camp at HBCSE, which picks India’s IBO team.
- NSEBIAPT
Selection for INBO is by NSEB score, within each class group. A student must reach the Minimum Admissible Score — half the average of the top ten scores, rounded down — and the target is 200 students per group, with state-wise representation.
Last reviewed 14 September 2026 · Source: iapt.org.in (official document)
- INBOHBCSE
The Indian National Biology Olympiad, on 31 January 2027, 1:30 pm to 3:30 pm. The list of selected students is published on IAPT’s website by 15 January 2027, and each must then register on HBCSE’s website for an admit card.
Last reviewed 14 September 2026 · Source: olympiads.hbcse.tifr.res.in
- OCSCHBCSE
The Orientation-cum-Selection Camp at HBCSE, Mumbai. Students are invited in order of INBO merit, to a target of 40; the camp’s theory and experimental tests choose the team. HBCSE will announce the 2027 dates by 15 January 2027.
Last reviewed 14 September 2026 · Source: olympiads.hbcse.tifr.res.in (official document)
- Pre-departure trainingHBCSE
The selected team trains at HBCSE in theory and experiment before leaving for the International Olympiad.
Last reviewed 14 September 2026 · Source: olympiads.hbcse.tifr.res.in
- IBO
The International Biology Olympiad. HBCSE’s 2026–27 brochure selects 4 students for India’s team, on a combined merit list of every student at the Biology OCSC.
Last reviewed 14 September 2026 · Source: olympiads.hbcse.tifr.res.in (official document)
Last reviewed 14 September 2026 · Source: olympiads.hbcse.tifr.res.in
When is NSEB 2026?
IAPT holds NSEB on Sunday 22 November 2026, after a student enrolment window, and HBCSE holds INBO on 31 January 2027. Each is listed below with its status as of today; OCSC 2027 has no announced date yet.
Next: NSEP, NSEC, NSEB, NSEJS — 22 November 2026 (Upcoming)
| Exam | Date | Status | Source |
|---|---|---|---|
| NSE student enrolmentExtended by IAPT. A student is enrolled by their centre in-charge or enrols individually. | 21 August – 16 September 2026 | Held | IAPT |
| NSEP, NSEC, NSEB, NSEJS | 22 November 2026 | Upcoming | IAPT |
| INPhO, INBO | 31 January 2027 | Upcoming | HBCSE |
Checked against the official sources on 14 September 2026. Confirm on the conducting body's site before you rely on a date.
Last reviewed 14 September 2026 · Source: iapt.org.in
Where can a student find past NSEB papers?
IAPT sells booklets of the past ten years’ question papers with solutions or answers, one per subject, Biology included; its brochure explains how to order them.
Last reviewed 14 September 2026 · Source: iapt.org.in (official document)
NSEB and INBO at Zigyan
Zigyan prepares students for the Biology Olympiad’s NSEB and INBO.
NSEB, answered
Can a Class 10 student sit NSEB?
Yes, if they meet IAPT’s eligibility rules, including the birth-date window. For 2026, IAPT opens NSEB to any student of Class 10, 11 or 12 on 30 November 2026 born between 1 July 2007 and 30 June 2012.
Last reviewed 14 September 2026 · Source: iapt.org.in
Are Class 11 and Class 12 students ranked together for INBO?
No. IAPT’s brochure splits the NSEB pool into Group A (Class XII on 30 November 2026) and Group B (Class XI or lower), and applies the selection rules to each group separately.
The target is 200 students from each group, and both groups sit the same NSEB and INBO question papers.
Last reviewed 14 September 2026 · Source: iapt.org.in (official document)
Is there negative marking in NSEB?
Yes, in the 48 single-answer questions: an incorrect choice loses 1 mark. The 12 multiple-answer questions score only when every correct option, and no incorrect one, is marked.
Last reviewed 14 September 2026 · Source: iapt.org.in (official document)
Can a student sit NSEB and NSEJS in the same year?
No. A student sitting NSEB 2026 must not be appearing in NSEJS 2026.
Last reviewed 14 September 2026 · Source: iapt.org.in (official document)
Can a student attend more than one Olympiad camp in a year?
No. HBCSE’s 2026–27 brochure allows one OCSC or IMOTC a year; a student who qualifies in more than one subject is invited to the camp ranked highest in their own preference order.
Last reviewed 14 September 2026 · Source: olympiads.hbcse.tifr.res.in (official document)
How does a student enrol for NSEB?
Through their school or another registered NSE centre, whose in-charge enrols them, or individually online on IAPT’s website during the enrolment window.
Last reviewed 14 September 2026 · Source: iapt.org.in
Who conducts NSEB and INBO?
IAPT conducts NSEB, the first stage. HBCSE is responsible for INBO and every stage after it, as both HBCSE’s stages page and IAPT’s brochure state.
Last reviewed 14 September 2026 · Source: olympiads.hbcse.tifr.res.in
Do the first two Olympiad stages need special coaching?
HBCSE’s stages page says the first two stages — the NSE and the INO — do not necessarily require specialised coaching outside the regular school system. Training is part of the programme from the third stage.
Last reviewed 14 September 2026 · Source: olympiads.hbcse.tifr.res.in
Official sources
Every fact in this guide was read from the conducting bodies’ own pages and documents. Confirm on them before you rely on a date or rule — they change from cycle to cycle.
Preparing for Olympiads?
Sit the scholarship test and talk to a mentor about which programme fits.