Characteristics that all living things have in common are: growth, reproduction, they are made up of cells, they respond and adapt to their environment, and obtain and utilize energy. An organism must exhibit all of these characteristics to be classified as a living thing. However, living organisms can have different levels of cellular organization.
For example, there are non-living things that can exhibit one or more of these characteristics, such as a sugar crystal. Although sugar crystals can grow, they are non-living substances.
Similarly, although all living organisms can have these basic characteristics, there are differences. For example, certain living organisms can reproduce through either asexual or sexual reproduction. Likewise, the level of cellular organization is more complex in a multicellular organism than in a unicellular one.
