Complete Guide to NDA biology topics for GAT 2026

The NDA GAT paper includes approximately 10 to 12 questions from Biology, focusing on fundamental concepts like cell biology, human physiology, and ecology. Mastering these topics is essential for scoring well in the General Science section, as these questions are fact-based and directly test your conceptual clarity for exam success.

What is the Exam?

The National Defence Academy (NDA) examination is conducted biannually by the Union Public Service Commission (UPSC). It is the gateway for young aspirants to join the Indian Army, Navy, and Air Force. The GAT (General Ability Test) is the second part of the written exam, carrying 600 marks, where the General Science component—including Physics, Chemistry, and Biology—plays a pivotal role in determining your final merit position.

Key Highlights 2026

• Exam Conducting Body: UPSC (Union Public Service Commission)
• Exam Mode: Offline (Pen and Paper)
• Total GAT Marks: 600
• General Science Weightage: Approx. 200 marks
• Biology Weightage: Approx. 40-50 marks
• Negative Marking: 0.33 for every incorrect answer
• Exam Date: Conducted twice annually (NDA I & II)

Syllabus 2026

Biology in the NDA GAT syllabus is designed to test a candidate's understanding of life sciences. Below is the breakdown of the high-yield topics.

Exam Pattern

The GAT paper is divided into two sections: Part A (English) and Part B (General Knowledge). General Science, including Biology, falls under Part B. To ace this, we recommend that you practice free mock tests for Defence on Exam Bhai to simulate the actual pressure of the examination hall.

Eligibility Criteria

As per the official notification available on upsc.gov.in, candidates must meet specific criteria:

• Age Limit: Candidates must be between 16.5 and 19.5 years old.
• Educational Qualification: 12th pass (or appearing) with Physics and Mathematics for Air Force/Navy; any stream for the Army wing.
• Citizenship: Indian, Subject of Nepal, or Tibetan Refugee (settled before 1962).

Application Process

The application process is strictly online through the UPSC website. Candidates must:

1. Register via the OTR (One Time Registration) portal on upsc.gov.in.
2. Fill in personal and academic details.
3. Select the preferred exam center.
4. Pay the application fee (exempted for SC/ST and Sons of JCOs/NCOs/ORs).
5. Upload necessary documents and submit.

Preparation Strategy

Success in the Biology section relies on NCERT books. We at Exam Bhai suggest the following:

1. NCERT is Bible: Read Class 9th to 12th Biology NCERT books thoroughly. Focus on the 'Summary' and 'Points to Ponder' sections.
2. Focus on Physiology: Questions on the human body (organs, diseases, nutrition) are most frequent. You can use our platform to evaluate your speed and accuracy in GAT Science to identify weak spots.
3. PYQs are Essential: Solve at least the last 10 years of UPSC NDA papers. Biology questions often repeat or follow a similar pattern.
4. Note-Making: Create a chart for vitamins, minerals, and their deficiency diseases—this is a goldmine for marks.
5. Test Environment: If you want to refine your preparation, you should join our targeted test series for NDA aspirants to bridge the gap between theory and application.

Cut-Off Trends

Historical data from upsc.gov.in indicates that the final cut-off for the written exam typically ranges between 340 to 360 marks out of 900. Since the GAT paper is highly competitive, scoring at least 120+ in the Science section (Physics + Chemistry + Bio) is considered a safe score to help cross the threshold.

Frequently Asked Questions

Q1: Is Biology mandatory for NDA? Yes, Biology is part of the General Science section in GAT. While Physics and Chemistry carry more weight, ignoring Biology can cost you 40+ marks.

Q2: Which books are best for NDA Biology? NCERT Class 9th, 10th, and the biology chapters from the 11th/12th NCERT Biology books are more than enough to cover the syllabus.

Q3: Does NDA have negative marking for Biology? Yes, there is a penalty of 0.33 marks for every incorrect answer in the GAT paper, including Biology.

Q4: How many questions appear from Biology? On average, 10 to 12 questions are asked in every NDA GAT paper from the Biology syllabus.

Q5: Are the questions in NDA biology theoretical or practical? They are mostly conceptual and fact-based. Expect questions related to human health, environment, and basic biological processes.

Q6: Can I skip Biology and still clear the cutoff? While it is theoretically possible to clear the cutoff by focusing on other subjects, it is highly discouraged. Biology is the 'low-hanging fruit' that provides quick, certain marks without complex calculations.