What term describes the various activities that living organisms perform to sustain life?

The term that accurately describes the various activities that living organisms perform to sustain life is life functions. This encompasses a wide range of processes essential for survival, including metabolism, growth, reproduction, and response to stimuli. Each of these functions is critical in maintaining homeostasis and ensuring the continuation of the species.

While "life processes" might seem similar and is often used interchangeably in some contexts, it typically refers to more specific types of biological functions rather than the broader scope implied by life functions. "Life cycles" refers specifically to the stages of development that an organism goes through during its life span and does not encompass the daily activities involved in sustaining life. "Living activities," while it sounds relevant, may lack the scientific rigor and specificity found in the term life functions.

Hence, life functions is the most appropriate term to encompass the various activities of organisms aimed at sustaining life.