Biology is the scientific study of life and living organisms. It is a broad natural science that explores the structure, function, growth, origin, evolution, and distribution of life across multiple levels of organization- from molecules and cells to organisms, populations, and ecosystems
. Central themes in biology include the cell as the basic unit of life, genes and heredity as the basis of inheritance, evolution as the driver of biological diversity, energy transformation to sustain life, and the maintenance of internal stability (homeostasis)
. Biology encompasses many subfields such as molecular biology, physiology, ecology, evolutionary biology, developmental biology, genetics, and systematics, among others
. Biologists study how living things behave, function, and interact with each other and their environments. This includes understanding how organisms grow, reproduce, and evolve, as well as how they are classified and related through evolutionary history
. Modern biology is grounded in the theory of evolution by natural selection and the molecular understanding of genes encoded in DNA
. In summary, biology is the comprehensive science that seeks to understand all aspects of life, from the smallest molecules within cells to the complex interactions within ecosystems
