Final answer:
Life in biological terms is defined by a set of characteristics including order, sensitivity to stimuli, reproduction, adaptation, growth and development, regulation/homeostasis, energy processing, and evolution. Reproduction alone, while essential, is not sufficient to define life, as exemplified by the status of viruses in biology.
Step-by-step explanation:
Defining Life in Biological Terms
While the ability to self-replicate is a critical aspect of life, it is not the sole definition. Biologists define life through a set of key characteristics or functions. Living organisms must exhibit several properties including order, sensitivity or response to stimuli, reproduction, adaptation, growth and development, regulation/homeostasis, energy processing, and evolution. It is the collective presence of these characteristics that defines a living organism, not just the ability to reproduce.
Virology offers a perfect example that challenges the simplicity of defining life solely as the ability to replicate. Viruses can replicate and affect other living organisms but are not considered living because they do not meet all the criteria for life laid out by biologists. Likewise, the study of early molecular evolution that led to life, although integral to understanding life's origins, operates in a space that precedes biological life as defined by these characteristics.