How to Prepare for IAT 2026 Biology Section: The IISER Aptitude Test (IAT) is the primary pathway for students who want to pursue undergraduate studies in Science and Research at the Indian Institutes of Science Education and Research (IISER). For UG admission to these institutes and the BSc (Research) programme at IISc Bangalore, IAT 2026 will be held in the fourth week of June 2026 (tentative). The application form for the test will tentatively be released in the fourth week of March 2026 at iiseradmission.in.
To crack the IISER Aptitude Test 2026, you must prepare for all four sections of the exam: Physics, Chemistry, Maths, and Biology. If you are struggling with the Biology section, this SciAstra article will help you learn strategies to prepare for the IAT 2026 Biology section.
Even if you are good at the subject and are looking for ways to boost your IAT 2026 preparation, this article can help you learn how to score 50+ in the IAT Biology section.
IAT 2026 Exam Pattern
If you are preparing for the Biology section of IAT 2026, you must understand the overall structure of the exam question paper by going through the exam pattern. The comprehensive overview of the IAT 2026 question paper is available below:
IAT 2026 Exam Pattern | |
Total Number of Questions | 60 Questions |
Sections | Four sections:
|
Marking Scheme |
|
Total Marks | 240 marks |
Test/Question Paper Language | Hindi and English |
Exam Duration | 180 minutes (3 hours) |
IAT 2026 Weightage of Biology Section
As per the IAT 2026 exam pattern, the weightage of the Biology section is equal to the other sections, which is 60 marks. Like the other sections, the total number of questions in the Biology section of IAT 2026 is 15. Therefore, this section is as important as the other sections, and candidates must prepare well to score well in it.
How to prepare for IAT 2026 Biology section
To prepare for the Biology section of IAT 2026, candidates must study concepts of Class 11 and Class 12 from NCERT Biology textbooks. For this, they should understand the IAT 2026 Biology syllabus, learn the concepts mentioned in the NCERT Biology textbooks of Classes 11 and 12, strengthen their knowledge of the high-weightage topics, and refer to the best books designed for IAT 2026 preparation. These strategies have been explained below.
Cover IAT 2026 Biology Syllabus
The first step towards preparing for the IAT 2026 Biology section is to know the exam syllabus for this subject. The syllabus of the IISER Aptitude Test 2026 Biology section has been provided below to help you with this step.
Diversity in the Living World:
The living world: The Diversity in the living world, Taxonomic categories.
Biological classification: Kingdoms (Monera, Protista, Fungi, Plantae, and Animalia), Viruses, Viroids and Lichens.
Plant kingdom: Algae, Bryophytes, Pteridophytes, Gymnosperms, Angiosperms.
Animal kingdom: Basis of classification of animals and Classification of Animals
Structural Organisation In Plants And Animals:
Morphology of flowering plants: The Root, The Stem, The Leaf, The Inflorescence, The Flower, The Fruit, The Seed, Semi-technical Description of a Typical Flowering Plant, Description of Some Important Families.
Anatomy of flowering plants: The Tissue System, Anatomy of Dicotyledonous and Monocotyledonous Plants
Structural organisation in animals: Organ and Organ System, Amphibian-Frog
Cell: Structure And Functions
Cell: the unit of life: A Cell, The Cell Theory, An Overview of Cell, Prokaryotic Cells, Eukaryotic Cells.
Biomolecules: Analysis of Chemical Composition of organisms, Primary and Secondary Metabolites, Biomacromolecules, Proteins, Polysaccharides, Nucleic Acids, Structure of Proteins, Enzymes
Cell cycle and cell division: Cell Cycle, Mitosis and Meiosis and their significance
Plant Physiology:
Photosynthesis in higher plants: Photosynthesis, Early Experiments, Location of photosynthesis, Pigments involved in Photosynthesis, Light Reaction, The Electron Transport, Synthesis and utilization of ATP and NADPH, The C4 Pathway, Photorespiration, Factors Affecting Photosynthesis.
Respiration in plants: Do Plants Breathe? Glycolysis, Fermentation, Aerobic Respiration, The Respiratory Balance Sheet, Krebs/Citric acid cycle.
Respiratory Quotient Plant growth and development: Growth, Differentiation, Dedifferentiation and Redifferentiation, Development, Plant Growth Regulators.
Human Physiology
Breathing and exchange of gases: Respiratory Organs, Mechanism of Breathing, Exchange of Gases, Transport of Gases, Regulation of Respiration, Disorders of Respiratory System.
Body fluids and circulation: Tissue Fluids-Blood, Lymph, Circulatory Pathways, Double Circulation, Regulation of Cardiac Activity, Disorders of the Circulatory System.
Excretory products and their elimination: Human Excretory System, Urine Formation, Function of the Tubules, Mechanism of Concentration of the Filtrate, Regulation of Kidney Function, Micturition, Role of other Organs in Excretion, Disorders of the Excretory System.
Locomotion and movement: Types of Movement, Muscle, Skeletal System, Joints, Disorders of the Muscular and Skeletal System.
Neural control and coordination: Neural System, Human Neural System, Neuron as Structural and Functional Unit of Neural System, Central Neural System.
Chemical coordination and integration: Endocrine Glands and Hormones, Human Endocrine System, Hormones of Heart, Kidney and Gastrointestinal Tract, Mechanism of Hormone Action.
Reproduction
Sexual reproduction in flowering plants: Flower structure, Angiosperms, Pre-fertilisation: Structures and Events, Double Fertilisation, Post-fertilisation: Structures and Events, Apomixis and Polyembryony.
Human reproduction: The Male Reproductive System, The Female Reproductive System, Gametogenesis, Menstrual Cycle, Fertilisation and Implantation, Pregnancy and Embryonic Development, Parturition and Lactation.
Reproductive health: Reproductive Health – Problems and Strategies, Population Explosion and Birth Control, Medical Termination of Pregnancy, Sexually Transmitted Diseases, Infertility
Biology In Human Welfare
Human health and disease: Common Diseases in Humans, Immunity, AIDS, Cancer, Drugs and Alcohol Abuse.
Microbes in human welfare: Microbes in Household Products, Microbes in Industrial Products, Microbes in Sewage Treatment, Microbes in Production of Biogas, Microbes as Biocontrol Agents, Microbes as Biofertilisers.
Genetics and Evolution
Principles of inheritance and variation: Mendel’s Laws of Inheritance, Inheritance of One Gene, Inheritance of Two Genes, Sex Determination, Mutation, Genetic Disorders.
Molecular basis of inheritance: The DNA, The Search for Genetic Material, RNA World, Replication, Transcription, Genetic Code, Translation, Regulation of Gene Expression, Human Genome Project, DNA Fingerprinting.
Evolution: Origin of Life, Evolution of Life Forms – A Theory, Evidence for Evolution, Adaptive Radiation, Biological Evolution, Mechanism of Evolution, Hardy–Weinberg Principle, Evolution, Origin and Evolution of Man
Biotechnology
Biotechnology: principles and processes: Principles of Biotechnology, Tools of Recombinant DNA Technology, Processes of Recombinant DNA Technology.
Biotechnology and its application: Biotechnological Applications in Agriculture and Medicine, Transgenic Animals, Ethical Issues.
Ecology
Organisms and populations: Populations, Logistic growth, Population interactions. Ecosystem
Biodiversity and conservation: Biodiversity and Biodiversity conservation.
Learn Biology NCERT Classes 11 & 12 concepts
The syllabus of IAT 2026 is based on concepts from NCERT Biology textbooks of Classes 11 and 12. Therefore, to build conceptual knowledge of the topics related to the IAT 2026 Biology section, candidates must study the NCERT textbooks thoroughly.
Focus on the high-weightage topics
Academic experts at SciAstra have analysed the IAT previous year question papers from 2017 to 2024 to identify high-weightage Biology topics for the exam. Based on this analysis, they have shortlisted the most important Biology chapters and concepts from which questions are frequently asked in the exam every year.
Candidates can focus more on these topics while preparing for the IAT Biology section to improve their score potential. The table below provides the number of questions from different topics in the IAT Biology section, based on previous year trends.
IAT Chapter-Wise Number of Questions (2017-2020) | |||||
Chapters | Year | ||||
2017 | 2018 | 2019 | 2020 | Total | |
Diversity | 1 | 1 | 1 | 1 | 4 |
Morphology and Anatomy | 1 | 0 | 2 | 1 | 4 |
Cell Biology | 2 | 2 | 1 | 1 | 6 |
Biomolecules | 1 | 0 | 1 | 0 | 2 |
Plant Physiology | 2 | 0 | 1 | 2 | 4 |
Human Physiology | 1 | 4 | 2 | 3 | 10 |
Genetics | 1 | 1 | 1 | 0 | 3 |
Molecular Biology | 0 | 1 | 1 | 1 | 3 |
Evolution | 1 | 0 | 1 | 1 | 3 |
Human Health & Disease and Microbes in Human Welfare | 2 | 2 | 1 | 1 | 6 |
Reproduction | 1 | 0 | 1 | 1 | 3 |
Biotechnology | 1 | 2 | 1 | 1 | 5 |
Ecology | 1 | 2 | 1 | 0 | 4 |
Source: sciastra.com | |||||
Check out below the number of chapter-wise questions asked in IAT Biology from 2021 to 2025.
IAT Chapter-Wise Number of Questions (2021-2025) | ||||||
Chapters | Year | |||||
2021 | 2022 | 2023 | 2024 | 2025 | Total | |
Diversity | 1 | 1 | 0 | 1 | 1 | 4 |
Morphology and Anatomy | 2 | 1 | 2 | 1 | 0 | 6 |
Cell Biology | 1 | 1 | 1 | 0 | 1 | 4 |
Biomolecules | 0 | 0 | 2 | 0 | 1 | 3 |
Plant Physiology | 3 | 2 | 1 | 2 | 2 | 10 |
Human Physiology | 1 | 3 | 1 | 3 | 3 | 11 |
Genetics | 0 | 3 | 1 | 1 | 2 | 7 |
Molecular Biology | 1 | 1 | 1 | 1 | 2 | 6 |
Evolution | 1 | 1 | 1 | 0 | 0 | 3 |
Human Health & Disease and Microbes in Human Welfare | 1 | 0 | 1 | 1 | 0 | 3 |
Reproduction | 0 | 0 | 2 | 2 | 1 | 5 |
Biotechnology | 2 | 1 | 1 | 2 | 1 | 7 |
Ecology | 2 | 1 | 1 | 1 | 1 | 6 |
Source: sciastra.com | ||||||
Based on the analysis, the number of questions asked from different chapters in the IISER Aptitude Test from 2014 to 2025 are mentioned as follows:
IAT 2026 Chapter-Wise Number of Questions (2017-2025) | |
Diversity | 8 |
Morphology and Anatomy | 10 |
Cell Biology | 10 |
Biomolecules | 5 |
Plant Physiology | 14 |
Human Physiology | 21 |
Genetics | 10 |
Molecular Biology | 9 |
Evolution | 6 |
Human Health & Disease and Microbes in Human Welfare | 9 |
Reproduction | 8 |
Biotechnology | 12 |
Ecology | 10 |
Source: sciastra.com | |
As per previous years’ IAT trends, the most important topics/chapters for the IAT 2026 Biology section are Human Physiology, Plant Physiology, Biotechnology, Morphology and Anatomy, Cell Biology and Genetics. Therefore, candidates should focus on studying these topics first to obtain a high score in the IAT 2026 Biology section.
Understanding IAT Biology Concepts Theoretically
To strengthen your knowledge about IAT Biology topics, you must learn theories related to them. The SciAstra Mastering Biology Volume 1 and Volume 2 books.
These books cover theoretical concepts of Classes 11 & 12 Biology textbooks. It also has diagrams to explain concepts visually. Purchase link below:
Mastering Biology Volume 1 (Class 11) | |
Mastering Biology Volume 2 (Class 12) |
Use the IAT 2026 Biology Books
Another effective way to prepare for the Biology section of IAT 2026 is to study from books prepared specifically for IAT 2026 Biology preparation. These books must have the following features:
Summary of chapters
Chapter-wise Previous Year Questions (PYQs)
Detailed solutions to questions
Important formula
All these features are available in the SciAstra IISER Aptitude Test Mock Test Book.
Get this book to boost your IAT 2026 preparation. Purchase link below:
SciAstra IISER Aptitude Mock Test Books | Buy Now (SciAstra Store) |
Buy Now (Amazon) | |
Buy Now (Flipkart) |
How to Attempt IAT Biology Section
To score well in the Biology section of IAT 2026, candidates need to approach it correctly. The right approach for PCB students is to learn all the facts related to the syllabus topics because Biology is one of their Class 11 and 12 subjects and they are well versed in it.
PCM students do not learn Biology in Classes 11 and 12. Therefore, they must study the subject conceptually by learning all the important theories and concepts. After this, they can learn Biology-related facts associated with the IAT syllabus topics.
How to Score 50+ in the IAT Biology Section?
Every year, SciAstra provides free Biology lectures for IAT preparation on YouTube and the SciAstra App. These lectures are called “One Shot Maharevision Videos”. Around 10-12 questions directly come from these lectures. Therefore, by using these free IAT preparation resources from SciAstra, you can score 50+ in the IAT 2026 Biology section.
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