Overview
The National Standard Examination in Biology (NSEB) is the first stage of India's biology olympiad pathway, conducted by the Indian Association of Physics Teachers (IAPT). Clearing NSEB leads to the Indian National Biology Olympiad (INBO), run by the Homi Bhabha Centre for Science Education (HBCSE), which selects India's team for the International Biology Olympiad (IBO).
Who can take part
For the 2025-26 cycle, NSEB was open to students who were in Class 10, 11 or 12 and would not complete Class 12 before November 30, 2025, born between July 1, 2006 and June 30, 2011 (both dates inclusive). Students must be eligible to hold an Indian passport, must have been studying in India (or in an Indian school system) since November 30, 2023 or earlier, and must not have started university by June 1, 2026. A student cannot appear for both NSEB and NSEJS (the junior-level exam) in the same year.
Stages and pathway
| Stage | Round | Conducted by |
|---|---|---|
| 1 | NSEB | IAPT |
| 2 | Indian National Biology Olympiad (INBO) | HBCSE |
| 3 | Orientation-cum-Selection Camp (OCSC) | HBCSE |
| 4 | International Biology Olympiad (IBO) | International |
Exam pattern
| Detail | NSEB 2025-26 |
|---|---|
| Level | Broadly equivalent to senior secondary (up to Class 12 CBSE) |
| Question type | Part A-1: 48 single-correct MCQs; Part A-2: 12 multiple-correct MCQs |
| Marking | Part A-1: +3 for a correct answer, −1 for a wrong one; Part A-2: +6 if all correct options are marked and none wrong, no negative marking |
| Total marks | 216 |
| Duration | 2 hours |
| Mode | Offline, OMR-based |
| Language | English or Hindi (regional-language papers optional, chosen at registration) |
Syllabus
NSEB covers Biology up to Class 12 CBSE level. The detailed syllabus is published by IAPT alongside the student brochure each cycle.
Results and awards
Selection to the Indian National Biology Olympiad (INBO) uses a Minimum Standard Score and Merit Index combined with a state-wise proportional representation rule, so that students from across India are represented rather than only the highest-scoring states. Shortlisted students are announced on the IAPT and HBCSE olympiad websites. Certificates are issued for all candidates, and merit certificates go to the top 10% at each centre; students attending the Orientation-cum-Selection Camp (OCSC) go on to be considered for India's IBO team.
Important dates
For the 2025-26 cycle, NSEB 2025 was held on Sunday, November 23, 2025, 2:30–4:30 pm. Online centre registration opened August 1, 2025, with enrolment closing September 21, 2025.
Fees
For the 2025-26 cycle, the fee was Rs. 300 per student for the exam, payable in cash to the centre in charge, or by bank transfer for students who self-enrol online.
How to register
Registration is normally through a school's registered NSE centre — the school's Principal or a Biology teacher enrols students. If a school cannot register a student, IAPT allows direct enrolment online through its own portal.
Preparation tips
Because Part A-1 penalises wrong answers (−1 mark) while Part A-2 does not, it is worth attempting every Part A-2 question but being selective in Part A-1. Working systematically through the Class 11–12 CBSE biology syllabus, and then past NSEB and INBO question papers published by IAPT and HBCSE, follows the level the exam is pitched at.
Is NSEB the same as INBO?
No. NSEB is the first-stage screening exam run by IAPT. Only NSEB qualifiers move on to the Indian National Biology Olympiad (INBO), run separately by HBCSE.
Is there negative marking in NSEB?
Yes, in Part A-1 (single-correct MCQs): +3 for a correct answer and −1 for a wrong one. Part A-2 (multiple-correct MCQs) has no negative marking.
Can a Class 9 student appear for NSEB?
No. NSEB is for students in Class 10, 11 or 12; younger students who qualify by age can instead appear for NSEJS, the junior-level National Standard Examination.
How do I register for NSEB if my school doesn't offer it?
IAPT allows students to enrol directly online through its own portal if enrolling through a school is not possible.