IISER Exam 2025 Important Topics: Check Subject Wise Important Chapters

Indian Institutes of Science Education and Research Entrance Exam 2025 ( IISER Entrance Exam )

Manisha
Manisha Kumari
Associate Senior Executive
Updated on May 1, 2025 12:50 IST

IISER Aptitude Test 2025 Important Topics will help test takers in boosting their IAT 2025 scores. IISER Entrance Exam 2025 will conducted on April 25, 2025at various IAT exam centres across the nation. Read this Shiksha article to learn about the subject-wise IISER aptitude test and important topics like Physics, Chemistry, Biology and mathematics. Also, check the subject-wise exam weightage in the examination.

 

IISER Entrance Exam 2025 Important Topics

The IAT (IISER Aptitude Test) is a crucial exam for students aiming for admission into the prestigious Indian Institutes of Science Education and Research (IISERs). It assesses your aptitude in four main science subjects: Physics, Chemistry, Mathematics, and Biology. While covering the entire syllabus is essential, focusing on important topics can optimize your preparation. IISER Entrance Exam 2025 will be conducted on May 25, 2025. While preparing for the exam, candidates will understand that the IAT Syllabus 2025 is vast. There is a lot of material that you need to cover in order to be successful in the exam.

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Also Read: IISER Entrance Exam Preparation 2025: Tips, Strategy & Guide 

The outstanding way to prepare for the exam is by conscientiously studying the IAT 2025 important topics. Emphasizing more on the IISER aptitude test important topics 2025 will enhance the student's performance at the time of the examination. It will also enhance their understanding and boost their confidence in the other BS-MS degree entrance exam, in which they are planning to appear in. In this Shiksha article, candidates will get the subject-wise important topics list, IISER previous year question paper, subject-wise syllabus, and all other latest updates.

Q:   Which books are suggested for Biology in IISER Entrance Examination preparation?
Q:   Which books are suggested for Chemistry in IISER Entrance Examination?
Q:   Which books are suggested for Mathematics in IISER Entrance Examination?
Table of content
  • IISER Aptitude Test 2025 Important Topics
  • Why it's important: Diagrams, hormonal control, and stages of development are frequently asked.
  • IISER Entrance Exam 2025: Chapter Wise Weightage
  • Advantages of Studying IAT 2025 Important Topics
  • IISER 2025 Entrance Exam Pattern
  • IISER 2024 Marks vs Rank

IISER Aptitude Test 2025 Important Topics

Focusing your preparation on the most heavily weighted topics in the exam syllabus maximizes the return on your investment of time and effort. By mastering these key areas, you can significantly increase your score and improve your chances of securing admission into your desired program. Here is the list of IISER subject-wise important topics for better preparation:

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IAT 2025 Important Chapter of Physics

  • Measurement and Units: Understanding fundamental units, dimensional analysis, errors in measurement. Go through Units and Measurement Class 11 Notes for a quick revision. 
  • Mechanics: Laws of motion, work, energy and power, momentum and impulse, circular motion, center of mass, gravitation.
  • Properties of Matter: Elasticity, fluids, surface tension, viscosity.
  • Thermal Physics: Kinetic theory of gases, laws of thermodynamics, specific heat capacity, change of state.
  • Oscillations and Waves: Simple harmonic motion, superposition of waves, sound waves, light waves.
  • Electrostatics: Electric charge, electric field, potential difference, Gauss's law, capacitance.
  • Current Electricity: What is Ohm's law, Kirchhoff's laws, circuits, magnetic effects of current.
  • Magnetism: Magnetic field, magnetic force, forces on a current-carrying conductor, electromagnetic induction.
  • Modern Physics: Photoelectric effect, Bohr model of the atom, nuclear physics.

Also Read: IISER Entrance Exam Preparation Tips & Guide 2025 

IAT 2025 Important Chapter of Chemistry

  • Basic Concepts: Atomic structure, periodic table, chemical bonding (ionic, covalent, metallic), chemical nomenclature.
  • States of Matter: Gaseous, liquid, and solid states, ideal gas laws, colligative properties.
  • Chemical Reactions: Stoichiometry, balancing equations, types of reactions (redox, precipitation, acid-base).
  • Equilibrium: Chemical equilibrium, Le Chatelier's principle.
  • Acids and Bases: Brønsted-Lowry and Lewis concept of acids and bases, pH, salts, hydrolysis.
  • Redox Reactions: Oxidation and reduction, balancing redox equations.
  • Organic Chemistry: Basic concepts, structure and properties of functional groups (alcohols, aldehydes, ketones, carboxylic acids, amines).
  • Chemical Kinetics: Rates of reactions, factors affecting reaction rates, order of reactions.
  • Inorganic Chemistry: Classification of elements, s-, p-, d-, and f-block elements, important compounds of some elements.

IAT 2025 Important Chapter of Mathematics

  • Algebra: Set theory, complex numbers, quadratic equations, inequalities, permutations and combinations, matrices and determinants.
  • Calculus: Differential calculus (limits, differentiation, applications of derivatives), integral calculus (integration, applications of integrals).
  • Trigonometry: Identities, trigonometric functions, graphs, applications.
  • Coordinate Geometry: Straight lines, circles, parabolas, hyperbolas.
  • Vector Algebra: Vectors, scalar and vector products, applications.
  • Probability and Statistics: Basic concepts of probability, permutation and combination, central tendency, dispersion.

IAT 2025 Important Chapter of Biology

Cell Structure and Function:
Key Concepts:

  • Cell theory
  • Prokaryotic vs eukaryotic cells
  • Cell organelles: structure and function
  • Biomolecules
  • Cell division: Mitosis and Meiosis

Why it's important: This chapter is heavily conceptual and frequently tested. Questions often revolve around organelle functions and phases of cell division.

Tip: Focus on diagrams and differences (e.g., between prokaryotic and eukaryotic cells, or mitosis vs meiosis).

Genetics and Evolution:
Key Concepts:

Q:   What are the factors to select the right IISER aptitude test preparation books?
Q:   Which books are suggested for Physics in IISER Entrance Examination 2023?
  • Mendel’s laws of inheritance
  • Dihybrid and monohybrid crosses
  • Sex determination
  • DNA structure, replication, and transcription
  • Genetic disorders
  • Evolutionary theories

Why it's important: This is a high-yield topic. IAT frequently includes tricky questions involving Punnett squares or pedigree charts.

Tip: Practice lots of genetics problems. Understanding inheritance patterns and calculations is essential.

Human Physiology:
Key Concepts:

  • Digestive system
  • Respiratory system
  • Circulatory system
  • Excretory system
  • Nervous and muscular system
  • Endocrine glands

Why it's important: At least 2–3 questions are expected from this section. Diagrams and function-based questions are common.

Tip: Use flowcharts and summary tables to remember hormone actions and feedback mechanisms.

Plant Physiology:
Key Concepts:

  • Photosynthesis
  • Respiration in plants
  • Transport in plants
  • Plant hormones
  • Growth and development

Why it's important: This area is rich in conceptual understanding and processes. Numerical and factual questions based on diagrams and reactions are common.

Tip: Focus on light and dark reactions, and functions of plant hormones (like auxins, gibberellins, etc.).

Ecology and Environment:
Key Concepts:

  • Ecosystems
  • Biodiversity and conservation
  • Environmental issues
  • Organisms and populations
  • Biogeochemical cycles

Why it's important: This is often considered easier and scoring. Questions are usually direct and based on facts.

Tip: Focus on understanding the food chains, ecological pyramids, and biogeochemical cycles.

Reproduction:
Key Concepts:

  • Reproduction in organisms
  • Sexual reproduction in flowering plants
  • Human reproductive system
  • Reproductive health
  • Gametogenesis and fertilization

Why it's important: Diagrams, hormonal control, and stages of development are frequently asked.

Tip: Understand the menstrual cycle, gametogenesis, and male/female reproductive structures clearly.

Biotechnology and Its Applications:
Key Concepts:

  • Principles of biotechnology
  • Genetic engineering (rDNA technology)
  • Applications in health and agriculture 

Utilize previous years' question papers and IISER Entrance Exam mock tests to get familiar with the exam format and difficulty level. Focus on strengthening your problem-solving skills and critical thinking abilities. Practice time management to be efficient during the exam. Refer to recommended textbooks and resources for in-depth learning.

By focusing on these important topics and employing effective study strategies, you can significantly increase your chances of excelling in the IAT 2025.

Also Read: Important Topics of Biology for IISER Entrance Exam 2025; Check Topics and Subject Weightage 

IISER Entrance Exam 2025: Chapter Wise Weightage

Check out the IISER exam 2025 chapter wise weighatge of Mathematics, Physics, Chemistry and Biology subjects from here:

Physics Chapter-wise Weightage

Chapter Approx. No. of Questions
Kinematics 1–2
Laws of Motion 1–2
Work, Energy & Power 1
Rotational Motion 1
Thermodynamics 1–2
Oscillations & Waves 1
Electrostatics 1
Current Electricity 1–2
Magnetism & EMI 2
Optics 1–2
Modern Physics (Atoms/Nuclei) 1–2
Chapter Approx. No. of Questions
Atomic Structure 1
Chemical Bonding 1–2
Thermodynamics 1
Equilibrium 1–2
Redox Reactions & Electrochem. 1
Chemical Kinetics 1
Organic Chemistry – Basics 1–2
Hydrocarbons & Functional Grps 2–3
Coordination Compounds 1
Biomolecules 1
Chapter Approx. No. of Questions
Sets, Relations & Functions 1
Trigonometry 1
Algebra (Complex, Quadratics) 2
Calculus (Limits, Derivatives) 2–3
Integrals & Applications 1–2
Vectors & 3D Geometry 2
Probability 1–2
Matrices & Determinants 1
Chapter Approx. No. of Questions
Cell Structure & Function 1–2
Genetics & Evolution 2–3
Human Physiology 3–4
Plant Physiology 2
Reproduction 1
Biotechnology 1
Ecology 2
Diversity of Life/Structural Org. 1

Advantages of Studying IAT 2025 Important Topics

There are several compelling reasons to prioritize the important topics for the IAT 2025:

Efficiency and Focus:

  • Maximize Your Score: By strategically focusing on high-yield topics, you can ensure you're spending your valuable study time on areas that are most likely to appear on the exam and contribute significantly to your score.
  • Confident Test Taker: Understanding these key areas will build a strong foundation, allowing you to tackle even more challenging questions with confidence.

Strategic Time Management:

  • Cover the Essentials First: Focusing on important topics first ensures you have a solid grasp of the core concepts before delving into less frequently tested areas. This strategy helps prevent last-minute scrambling and ensures you cover the crucial material.
  • Time for Advanced Topics: Once you've mastered the essential topics, you'll have more time and mental energy to explore more advanced concepts that might give you an edge on the exam.

Exam Pattern and Difficulty:

  • Alignment with the Exam: Focusing on important topics aligns your studies with the actual exam's content and difficulty level. This ensures you're practising the types of questions you'll encounter and developing the skills required to answer them effectively.
  • Confidence in Answering Repeated Questions: Previous years' papers and analysis from experts often reveal frequently tested topics. Mastering these areas increases the likelihood of correctly answering questions that reappear on the exam.

Overall Success:

  • Strong Foundation for Deeper Understanding: Grasping the key concepts lays the groundwork for deeper understanding across all scientific disciplines tested on the IAT. This not only benefits exam performance but also prepares you for future academic endeavours in science.
  • Reduced Test Anxiety: Feeling prepared and confident in your knowledge of the IISER exam important topics significantly reduces test anxiety. This allows you to approach the exam with a clear mind and perform to your full potential.
IISER Entrance Exam 2025 Pattern IISER Entrance Exam 2025 Application Form IISER Entrance Exam 2025 Important Dates
IISER Entrance Exam 2025 Analysis IISER Entrance Exam 2025 Books IISER Entrance Exam 2025 Admit Card

IISER 2025 Entrance Exam Pattern

The IISER Entrance Exam Marking Scheme is as follows:

Subject

No. of Questions

Marks

Physics

15

60

Chemistry

15

60

Biology

15

60

Mathematics

15

60

Total

60

240

IISER 2024 Marks vs Rank

IAT 2024 candidates' ranks will be based on their combined scores from the four sections (Physics, Chemistry, Mathematics and Biology). The exam comprises 60 questions with a total score of 240 marks. Below is a table for the expected IISER 2024 ranks corresponding to different score ranges.

IISER 2024 Score (Out of 240) Expected IISER 2024 Rank
200 and above Rank 1 to 80
200-160 Rank 81- 200
160- 110 Rank 201 to 800
110-95 Rank 800 to 1500
95-75 Rank 1500- 2000
< 60 Above 2000

Read More: IAT Exam 2024 Cut Off (OUT): Check IISER, IISc Banglore & IIT Madras Cut Off/ Closing Rank Here 

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About the Author
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Manisha Kumari
Associate Senior Executive
Being a post-graduate and BEd degree holder, I'm an innovative, task-driven and immensely motivated science enthusiast, making me a passionate content writer. I love providing meaningful and constructive articles in Read Full Bio
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Answered 2 months ago

With a 7,000 rank in the SC category, admission to any IISER (including newer campuses) is not possible as per 2025 cutoffs. Cutoff ranks for SC category in IISERs generally close between 125 (most competitive) and 750 (least competitive).

P

PRINCE MISHRA

Contributor-Level 7

Answered 2 months ago

IISER Berhampur cutoff 2025 for the BS + MS course across multiple specialisations stood at 3299 during the Round 1 cutoff for the students belonging to the General AI quota. So, considering the first-round cutoff rank, candidates must target to secure a rank up to 3299 and lower to improve their ch

...Read more

R

Rashmi Sinha

Contributor-Level 10

Answered 2 months ago

IISER Mohali cutoff 2025 has been released for different categories of students under the AI quota. For the General category, the cutoff rank for BS + MS admission across multiple specialisations was 1778. To view the category-wise ranks, refer to the table below:

CategoryBS + MS
General1778
OBC1358
SC520
ST263
EWS480
PWD50112

R

Rashmi Sinha

Contributor-Level 10