Biology is the study of life and living organisms. Since it embraces all living things, it is perhaps the most fascinating branch of science. The new inventions and discoveries have helped greatly in continuously testing and searching the truth and unfolding the mysteries of life whether plants, animals or microscopic life. During the past some years, biology has shifted its focus from the structure of living organisms to looking more at how they work and function. These advances in biological knowledge raise new issues. The present book will help you to understand and contribute to the biological revolution which is taking place in our lives.