"Biology" is life and living organisms, including their physical structure, chemical processes, molecular interactions, physiological mechanisms, development and evolution.
What are the taxonomy and how does it help identify and categorization? What is the relationship between living organisms and it's non-living surronding? What is the history of biology? How can the study of biology hep with the future of humans? are a few themes of "Biology".
Charles Darwin. Gregor Mendel. Louis Pasteur are some authorities of "Biology".
Some motivations are learn the relationship between the living organisms and our everyday lives. Help understand the various systems of nature and how they interact with eachother.