Biology is the study of life. Biologists attempt to understand the living world at all levels using many different approaches and techniques. At one end of the scale is the cell, its molecular construction and complex metabolic reactions. At the other end of the scale biologists investigate the interactions that make whole ecosystems functions.
Cell biology, molecular biology, genetics, ecology, evolution & biodiversity, human physiology
Additional higher level (AHL):
Nucleic acids, metabolism, cell respiration & photosynthesis, plant biology, genetics & evolution, animal physiology