Final answer:
Developmental psychology is the field that studies physical and psychological changes throughout one's life, from conception to death, across three developmental domains.
Step-by-step explanation:
The study of psychological and physical changes from conception to death is known as developmental psychology. This field encompasses a range of topics including physical maturation, cognitive skills, moral reasoning, social behavior, and other psychological attributes. Developmental psychology views growth as a lifelong process and investigates how humans change across three developmental domains: physical, cognitive, and psychosocial development, which involve changes in the body and brain, learning and mental processes, as well as emotions, personality, and social interactions.