Checked 3 October 2026. Every link was opened on the date shown and returned a PDF. The files are hosted by IIT Madras on the GATE 2027 site; if one moves, the same files are on its Download page. The question-mix counts are from the official keys and will not change.
The official GATE site hosts six Biotechnology papers with their answer keys, from 2021 to 2026, free to download. They are the best practice material that exists for the paper, and the question mix has changed enough between 2022 and 2026 that how you use them matters. This page links all twelve files, shows what changed, flags the quirks in the papers and keys, and sets out a way to work through them.
Official GATE BT papers and keys
- GATE 2026 (IIT Guwahati) — Question paper · Answer key
- GATE 2025 (IIT Roorkee) — Question paper · Answer key
- GATE 2024 (IISc Bengaluru) — Question paper · Final answer key
- GATE 2023 (IIT Kanpur) — Question paper · Answer key
- GATE 2022 (IIT Kharagpur) — Question paper · Answer key
- GATE 2021 (IIT Bombay) — Question paper · Answer key
All twelve are on the GATE 2027 Download page, year-wise for 2021 to 2026. That page also links a bulk folder of papers for 2007 to 2026 on Google Drive; we did not open it, so we do not vouch for what it holds.
The 2021 paper and key are scanned images with no text layer, so you cannot search them or copy from them. The other ten files are text PDFs. The 2024 file is titled a final answer key; the other keys are plain answer keys.
What each paper looked like
| Paper | Subject MCQ / MSQ / NAT | Subject questions: 1-mark / 2-mark | Largest section by our count |
|---|---|---|---|
| GATE 2026 | 21 / 14 / 20 | 25 / 30 | Engineering Mathematics (17) |
| GATE 2025 | 23 / 15 / 17 | 25 / 30 | General Biology (22) |
| GATE 2024 | 30 / 10 / 15 | 25 / 30 | Engineering Mathematics (15) |
| GATE 2023 | 22 / 7 / 26 | 25 / 30 | General Biology (17) |
| GATE 2022 | 27 / 8 / 20 | 25 / 30 | Fundamentals of Biological Engineering (17 marks) |
From the official answer keys, subject part only. Every paper has 65 questions for 100 marks: ten General Aptitude questions (five of one mark, five of two marks) and 55 subject questions, 25 of one mark and 30 of two marks. The 25-and-30 split has not moved in five years. What has moved is the type of question.
From the official answer keys; each bar is 55 questions. MCQs have fallen from 30 in 2024 to 21 in 2026.
For the section-by-section marks of each paper, see our GATE BT topic-wise weightage, which indexes every question.
What changed between 2022 and 2026
Four changes in how the paper asks
- One-mark MSQs appeared in 2025. Up to 2024 every multiple-select question was worth two marks (8, 7 and 10 of them). In 2025 there were seven one-mark MSQs and eight two-mark ones; in 2026 four and ten. An MSQ earns marks only if you pick exactly the right set and nothing else; there is no partial credit and no negative marking.
- Fewer MCQs. 30 in 2024, 23 in 2025, 21 in 2026. Wrong MCQs cost 1/3 or 2/3 of a mark, so each of those 30 was a place to lose marks; in 2026 there were nine fewer.
- More numerical answers, with ranges. NAT questions rose from 15 in 2024 to 17 and 20. 2023 was the peak with 26, which carried 46 of the 85 subject marks. Many NAT keys accept a range (2025: 12 of 17; 2026: 9 of 20), so how you round matters.
- An MSQ can have one correct option. In 2026, four MSQs (Q30, Q44, Q45, Q47) had a single option in the key, and in 2024 Q53 did; the 2022 and 2023 keys list only multi-option sets. Do not assume an MSQ has two right answers.
Counts are ours, read from the official answer keys.
| Paper | Marks from MCQ | Marks from MSQ | Marks from NAT | Share with no negative marking |
|---|---|---|---|---|
| GATE 2022 | 38 | 16 | 31 | 55.3% |
| GATE 2023 | 25 | 14 | 46 | 70.6% |
| GATE 2024 | 38 | 20 | 27 | 55.3% |
| GATE 2025 | 36 | 23 | 26 | 57.6% |
| GATE 2026 | 26 | 24 | 35 | 69.4% |
Subject marks only. MSQ and NAT carry no negative marking; in 2026, 59 of the 85 subject marks came from questions where a wrong answer cost nothing, against 47 in 2024. A NAT or MSQ you cannot finish still earns zero, so the saving is in the downside, not the upside.
Quirks in the papers and keys
Things that can trip a self-marking session
- 2023 numbering. The Fabry-disease numerical question is printed a second time as "Q.20" in the paper. It is question 30; the key lists it as 30 (answer 25). The real question 20 is about the sequence of events in bacteriophage infection.
- 2022 MTA. The 2022 key lists "MTA" instead of an option for Q10, a two-mark General Aptitude question. In GATE keys the abbreviation means marks to all candidates; the key itself does not define it.
- Section names. The key calls the subject part "BT" and the first ten questions "GA". The paper and key do not mark which of the 55 subject questions is Engineering Mathematics; the brochure says 13 marks.
- Session numbers. Keys carry a session number (2026 shows 2, 2025 shows 7). These count the sessions across the whole exam window, in order, not a first or second sitting of BT: the paper was held once, on Sunday 16 February 2025 in the forenoon (the seventh of eight sessions) and Saturday 7 February 2026 in the afternoon (the second session).
- Old syllabus content. The 2022 to 2026 papers were set on older syllabi. The 2027 syllabus no longer names material and energy balances, thermodynamics or transport processes, which supplied 63 of 425 subject marks in these five papers by our count. Mark those questions in the index and treat them as lower priority, not as zero: Bioreaction Engineering still names related ideas such as diffusion effects.
How to use six papers
With six papers, do not burn them as mock tests in the first week. Work each one twice: once by topic, while you study, and once as a timed paper near the end.
| Stage | Use | Why |
|---|---|---|
| While you study each section (October to December) | Pull that section's questions from the five text papers using the question index on our weightage page and solve them together | Shows how deep each topic is examined, and which question types it comes in |
| First timed paper (early December) | The 2022 paper, 3 hours, self-marked with the real rules | The oldest in the set; use it while pacing is still being learned |
| Mid and late December | 2023 and 2024 papers, timed | Different mixes: 2023 is NAT-heavy (46 marks), 2024 is MCQ-heavy (38) |
| January | 2025 paper, then 2026 as a dress rehearsal | The two newest papers show the current question mix: one-mark MSQs, more numerical answers |
GATE BT previous-paper tracker
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Marking yourself honestly
Mark with the real rules: +1 or +2 for a correct answer; minus 1/3 for a wrong one-mark MCQ and minus 2/3 for a wrong two-mark MCQ; nothing lost on a wrong MSQ or NAT; no partial marks on an MSQ; and a NAT is right only if your value is inside the key's range. The calculator shows when a guess on an MCQ is worth taking.
Should you guess? The negative-marking calculator
Pick the question type and how many of the four options you can confidently rule out. The calculator shows your expected marks from answering versus leaving it blank.
Two numbers are worth tracking from paper to paper. The first is the marks you lose to negative marking on MCQs; you can cut it in a week. The second is "nearly right" MSQs, which is a precision problem you fix by judging each option on its own. Both are invisible if you only look at the total.
Three mistakes people make with six papers
- Using them all as mocks early. By January there is nothing unseen left. Do them by topic first and keep the 2026 paper untouched as a full paper until the last weeks.
- Reading the solution after a minute. A question you give up on too early is a question wasted. Give each one a real attempt and write down where you got stuck before you look.
- Revisiting only the questions you got wrong. Re-solve the ones you got right by luck as well; a correct guess on an MCQ looks exactly like knowledge in the total.
The papers do not tell you what to do about the 2027 syllabus change. For that, read our guide to the 2027 BT syllabus and a preparation plan.
Practise it, don't just read it
Between papers, topic quizzes give you fresh questions on the areas the papers expose.
The ProSyllabus GATE BT library has nine topic quizzes of ten questions each: Michaelis Menten Enzyme Kinetics Fundamentals, Mendelian Inheritance Patterns Fundamentals, Monod Microbial Growth Model Fundamentals, Oxygen Transfer in Bioreactors Advanced Challenge, Metabolic Flux Balance Analysis Advanced Challenge, and the Molecular Tools, Analytical Tools, Computational Tools and Recombinant DNA Technology practice quizzes. Note that oxygen transfer (kLa) sits under the Transport Processes heading of the 2026 syllabus, which the 2027 syllabus no longer lists; the other eight map onto topics that are still named.
Frequently asked questions
Where can I download GATE BT previous year question papers?
The official GATE 2027 website, run by IIT Madras, hosts the BT question paper and answer key for each year from 2021 to 2026 on its Download page, free. Direct links to all twelve files are on this page.
Are GATE BT answer keys official?
Yes. The keys listed here are published on the official GATE site by the organising institute. The 2024 file is titled a final answer key. They show the key or accepted range for every question and the marks.
Is there negative marking in GATE BT?
Only for MCQs: one third of a mark for a wrong one-mark MCQ and two thirds for a wrong two-mark MCQ. MSQ and NAT questions carry no negative marking, and an MSQ gets no partial marks.
How many numerical answer questions are in the GATE BT paper?
In the subject part, 20 of 55 in 2026, 17 in 2025, 15 in 2024, 26 in 2023 and 20 in 2022, according to the official answer keys.
Can I use old GATE BT papers for GATE 2027 when the syllabus changed?
Yes, but not blindly. The 2027 syllabus no longer names material and energy balances, thermodynamics and transport processes, which gave about 15% of the subject marks in the 2022 to 2026 papers by our count. Use the index on our weightage guide to mark those questions and treat them as lower priority.
More in this series
- GATE Biotechnology qualifying marks by year and category, 2023–2026
- GATE Biotechnology topic-wise weightage, counted from the 2022–2026 papers
- M.Tech and PhD after GATE BT: what IISc, IITs and NITs publish
- GATE BT 2027 syllabus changes and a week-by-week preparation plan
- GATE Biotechnology expected cutoff, IIT/IISc admission scores and placements (older guide)
- GATE 2026 Biotechnology paper analysis (older guide)
- GATE Biotechnology complete guide (older guide)
- GATE BT notice board: official updates
- GATE XL vs GATE BT vs CSIR NET Life Sciences: which to write
- GATE XL marks vs score vs rank calculator
Sources
- official — GATE 2027 Download page: question papers and answer keys
- official — GATE 2026 BT question paper
- official — GATE 2026 BT answer key
- official — GATE 2025 BT question paper
- official — GATE 2025 BT answer key
- official — GATE 2024 BT question paper
- official — GATE 2024 BT final answer key
- official — GATE 2023 BT question paper
- official — GATE 2023 BT answer key
- official — GATE 2022 BT question paper
- official — GATE 2022 BT answer key
- official — GATE 2021 BT question paper
- official — GATE 2021 BT answer key
- official — GATE 2027 Information Brochure, revised 27 Sep 2026
- official — GATE 2026 examination schedule (IIT Guwahati)
- official — GATE 2025 examination schedule (IIT Roorkee)
official = a document published by the conducting body. reported = a news or coaching site we could not check against an original. Where sources disagree this page says so rather than picking one.
