In other words, they regulate their bodies and other internal structures to certain normal parameters. Living creatures respond to stimuli. Cues in their environment cause them to react through behavior, metabolism, and physiological change. Living things reproduce themselves by making copies of themselves. Reproduction can either be sexual or asexual .
Sexual reproduction involves the fusing of haploid genetic material from two individuals.
This process creates populations with much greater genetic diversity . Organisms tend to grow and develop. Growth involves the conversion of consumed materials into biomass, new individuals, and waste. Life adapts and evolves in step with external changes in the environment through mutation and natural selection . This process acts over relatively long periods of time.