Rock the GED Science 2025 – Blast Your Way to Success!

The term for a living thing that has or can develop the ability to act or function independently is "organism." Organisms are individual forms of life, ranging from single-celled bacteria to complex multicellular beings like plants and animals. They exhibit characteristics of life, which include growth, reproduction, metabolism, and response to stimuli.

This definition highlights the independent nature of organisms—they can perform essential life processes without requiring other living entities to provide support. In contrast, the other terms given in the question refer to various biological or physical concepts but do not encapsulate the independence inherent in living things. For example, nuclear fusion relates to a process of energy production in stars and does not pertain to living organisms; a nucleus is a structure found within cells that houses genetic material but cannot function independently as a living entity; an organ is a grouping of tissues that work together for a specific function within a larger system, but it cannot survive on its own without the context of the whole organism. Therefore, organism is the correct term for a living thing defined by its independent functioning ability.