There is converging evidence that decision-making, including economic decision-making, is driven by biological mechanisms that shape the way we process information when we make decisions. Understanding these mechanisms is critical to a better modeling of human behavior. This section reviews principles of biology. It overlaps and extends notions covered in the AP biology course.

Cell biology is the study of the structure and the functions of cells. The cell is the basic structural, functional, and biological unit of all known organisms. Cell biology encompasses both prokaryotic and eukaryotic cells.

Heredity is the passing on of traits from parents to their offspring; either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic information of their parents.

Evolution and diversity result from the interactions between organisms and their environments over long periods of time. Organisms continually adapt to their environments through natural selection.

Physiology is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical and physical functions in a living system.

The endocrine system is the collection of glands that produce hormones that regulate metabolism, growth and development, tissue function, sexual function, reproduction, sleep, and mood, among other things.

The nervous system is a complex collection of nerves and cells called neurons that transmit signals between parts of the body.

See also the section "Neuroscience"

Reproduction is the biological process by which new organisms (offspring) are produced from their parents. Some organisms use asexual reproductino, while others use sexual reproduction.

Embryonic development is the development of an animal or plant embryo.

The immune system is a network of cells and proteins that defends the body against infection. It keeps a record of every germ it has ever defeated so it can recognise and destroy it quickly if it enters the body again.

Ecology studies the spatial and temporal patterns of the distribution, diversity and abundance of organisms.

Animal behavior includes all the ways animal interact with each other and their environment. Behaviors may be innate or learned through experience. They evolve under evolutionary pressure to enhance the fitness of organisms or species.