The Book "Cytogenetics" is designed primarily for undergraduate and postgraduate students of Indian Universities. The inclusion of greater detail than is usually found in texts of under graduate level is deliberate. This has resulted in corresponding advancement of University curricula, and in biology the emphasis has shifted to cell biology, genetics and physiology. It is hoped that this approach will meet the needs of undergraduate students, and also provide sources to post-graduate students for a more advanced study. Cell biology is an integrated discipline including material from the fields of cytology, cytogenetics, physiology, biochemistry, biophysics, and microbiology. The intellectual challenge involved in the involved in the study of cells has also attracted scientists from the physical sciences, and the field today constitutes a frontier of biological knowledge. All attempts have been made in the present work to provide an integrated approach covering cell structure and molecular biology. It is expected that the present book with updated information will be useful to the readers.