Welcome to Introductory Biology, a foundational text for B.Sc. (Hons.) Agriculture students according to recommendation of ICAR Sixth Dean’s Committee Report . This book explores the core principles of biology and their vital applications in agriculture, from understanding cellular processes to the diversity and evolution of life. It connects theoretical concepts with practical insights into plant growth, reproduction, classification, and the role of animals in farming systems. Each chapter builds a strong foundation, encouraging critical thinking through examples, case studies, and questions. More than a textbook, it is a guide to understanding life, addressing challenges in sustainable agriculture, biodiversity conservation, and food security.