Cellular organization, reproduction, metabolism, homeostasis, heredity, response to stimuli, growth and development, and adaption through evolution.

• A. Tools of Science
• B. Development
• C. Characteristics of Life
• D. Observations

Answer: (C)

What defines living things is a specific set of features they share. The list you’re given—cellular organization, reproduction, metabolism, homeostasis, heredity, response to stimuli, growth and development, and adaptation through evolution—together describe what life can do. Each trait shows a fundamental ability: organized cells form the structure of life; reproduction passes on information to new generations; metabolism uses and transforms energy; homeostasis keeps internal conditions steady; heredity transmits traits; response to stimuli allows interaction with the environment; growth and development expand an organism’s form and function; and evolution-driven adaptation explains long-term changes in populations. Because these traits collectively define living systems, this option is the best choice. The other terms refer to how we study life or aspects of life without defining what life itself is—tools of science, observations, or a process within life—so they don’t capture what living things are.