Cell biology is a fascinating branch of biological Sciences, providing answers to hitherto unanswered questions. It is the mother science to areas such as Molecular Biology, Molecular Genetics, Biotechnology, Recombinant DNA technology, etc. During the last few decades the science of cell biology has grown at an unprecedented pace with the consequence that voluminous information has accumulated on the subject. Cell and Molecular Biology is intended as a textbook for graduate (Honors) and postgraduate students of life sciences. It is being prepared in accordance with the UGC guidelines.