The revised edition of this bestselling textbook provides latest and detailed account of vital topics in biology, namely, Cell Biology, Genetics, Molecular Biology, Evolution and Ecology . The treatment is very exhaustive as the book devotes exclusive parts to each topic, yet in a simple, lucid and concise manner. Simplified and well labelled diagrams and pictures make the subject interesting and easy to understand. It is developed for students of B.Sc. Pass and Honours courses, primarily. However, it is equally useful for students of M.Sc. Zoology, Botany and Biosciences. Aspirants of medical entrance and civil services examinations would also find the book extremely useful.