How to Use This Book

A Note to the Reader

In-text citations use the author-date style (Author, Year). Full details are in the End References at the back of the book. Web sources were consulted in October 2026.

This book follows the structure of the Sri Lankan GCE Advanced Level Biological Science stream, which leads to medicine, dentistry, veterinary science, allied health, agriculture, and the life sciences. Syllabi, paper structures, and admission rules are revised from time to time, and a general education reform is under way. Always confirm details with your teacher, the National Institute of Education (NIE), the Department of Examinations, and the University Grants Commission (UGC). Nothing in this book is medical advice.

Contents

1. Introduction: The Biological Science Pathway 1

2. Study Skills, Exam Strategy, and Wellbeing 5

3. Biology I: Introduction to Biology and the Chemical Basis of Life 8

4. Biology II: The Cell 12

5. Biology III: Energy and Metabolism 16

6. Biology IV: Evolution and the Diversity of Organisms 19

7. Biology V: Plant Form and Function 22

8. Biology VI: Animal Form and Function I (Nutrition, Circulation, Gas Exchange, and Excretion) 25

9. Biology VII: Animal Form and Function II (Defence, Coordination, Senses, and Homeostasis) 29

10. Biology VIII: Locomotion, Reproduction, and Development 33

11. Biology IX: Genetics 36

12. Biology X: Molecular Biology and Recombinant DNA Technology 39

13. Biology XI: Environmental Biology 43

14. Biology XII: Microbiology and Infectious Disease 46

15. Chemistry I: Foundations (Atomic Structure, Bonding, Calculations, Gases, and Energetics) 49

16. Chemistry II: Kinetics, Equilibrium, Electrochemistry, and Biological Buffers 52

17. Chemistry III: Inorganic and Environmental Chemistry 55

18. Chemistry IV: Organic Chemistry and Biomolecules 58

19. Physics I: Mechanics, Fluids, Waves, and Thermal Physics with Medical Applications 61

20. Physics II: Electricity, Magnetism, Electronics, and Modern Physics with Medical Applications 65

21. Agricultural Science I: Agro-ecology, Soil, Plant Nutrition, Land Preparation, and Irrigation 68

22. Agricultural Science II: Propagation, Breeding, Plant Physiology, Pest Management, Post-Harvest, and Paddy 73

23. Agricultural Science III: Animal Husbandry, Food and Nutrition, Sustainable Agriculture, and Economics 77

24. Medicine, Health Sciences, and Other Careers 80

25. A Two-Year Plan and Checklist 83

26. Conclusion 85

27. Glossary 86

End References 88

CHAPTER 1