Which of the following best describes "physiology"?

Physiology is best defined as the study of the functions and processes of living organisms. This encompasses how cells, organs, and systems within an organism operate, interact, and respond to external stimuli to maintain homeostasis. Understanding physiology involves exploring various functions such as respiration, circulation, digestion, and neural processes, which are crucial for the survival and health of organisms.

In contrast, the structure of living organisms refers to anatomy, which focuses on the physical components and organization within an organism. The study of animal behaviors relates more closely to ethology or psychology, examining how animals interact with their environment and each other. The examination of genetic makeup pertains to genetics, which investigates heredity, gene function, and the variations of organisms. Therefore, the distinction lies in physiology specifically addressing how organisms function, making it the most accurate description among the options provided.