The present book “Concepts of Life Sciences” has been designed to cover the syllabus of CSIR-NET and also related examinations like DBT-JRF, GATE-Life Sciences, ICAR, ICMR, etc. The contents have been presented in a simple and concise manner. Each chapter contains logically organised information according to the recent trends and pattern of CSIR-NET examination. It is an easy-to-follow study guide which focuses on fundamentals and concepts with expanded coverage of critical topics. The text describes all topics of Life Sciences so that even a beginner can easily understand the theoretical aspects. The book is unique in its broad subject coverage, incorporating all fundamental aspects of life sciences and provide a logical flow of concepts. The book covers a wide range of topics including molecules and their interaction relevant to biology, Cellular organisation, fundamental processes, cell communication and cell signalling, developmental biology, system physiology (animals and plants), inheritance biology, diversity of life forms, ecological principles, applied biology and methods in biology. The book is designed to serve a wide range of students in diversified fields of life sciences: plant science, animal science, biotechnology, microbiology, biochemistry, and molecular biology. The systematically arranged contents adhere to make life sciences as an interesting discipline. As a further aid to readers, all chapters have been provided with well-illustrated diagrams to explain the principles and theories behind each topic.