Preface The prime objective of this book is to provide knowledge in the field of agriculture for both the graduate and post graduate students. This book is the collection of questions from several different subjects like Genetics, Seed science and technology, Biotechnology, Environmental Science, Entomology and Nematology. This book has been prepared keeping in view that course requirement in different competitive exams. Material content in the book largely comes from the notes prepared by the authors and some are memory based. The topics mainly covered in this book are breeding programme, mode of reproduction, pollination, principles of pollinated crops, GMOs, seed production, seed testing, seed certification, seed storage, seed treatments, seed act, Mendel principles, dominance relationship, mutation, gene concept, inheritance, plant tissue culture, linkage, environmental pollution, biological diversity and its conservation, environmental problems and protection, sustainable development, natural resources, ecosystem, important species of plant parasitic nematodes, some important nematecides, history of entomology, morphology of insects, anatomy of insects, taxonomy of insects, some important harmful insects, important disease of field crops and horticultural crops. I wish to acknowledge and express my sincere thanks to God and deep gratitude to the Phonics Group of Institutions, Roorkee especially the chairman (Er. Cherub Jain), the director (Dr. K.K. Gautam)& (Dr. M.S. Rana) the assistant director (Dr. Bhuvnender Chaudhary) and the registrar (Mr. Amit Gautam) for their keen interest and providing us the opportunity to prepare the manuscript. I appreciate my colleagues Mr. Ram V. Rawat, Dr. Purna Jana for their immense help and support. Also I am thankful to Ms. Garima Sharma, Mr. Nirbhay Ahlawat, Dr. R. A. Jan, Dr. Richa Chauhan, Ms Portia D. Singh and Ms. Prastuti Mishra and staff Mr. Ajay Kumar of my department (Department of Agriculture) for their generous support. I also extend my thanks to one of our sincere student Mr. Nitish Mandal for his sincere hard work. At the end I wish to record my deep sense of love and respect to my mom Sadhana, Dad Dr. Ram bhushan, brother Anupam & Abhishek, bhabhi Jaya, sister Vandana, jija Jitendra, niece & nephew Anvi, Shubh, Krishna and my husband Anil for their immense help and excellent moral support ever and always.