Characteristics of Living Things-What makes something alive?

There is no single definition of life that is universally accepted. However, most biologists would agree that the following are essential characteristics of life:

  • Organization: Living things are organized into cells, which are the basic units of life.


  • Metabolism: Living things take in energy and use it to build and maintain their bodies.

take in energy

  • Growth: Living things grow and develop over time.

grow develop

  • Reproduction: Living things reproduce, creating new individuals of their own kind.


  • Response to stimuli: Living things respond to their environment.

respond stimuli

All living things contain genetic material such as DNA.


In order to be considered living, an organism must contain each of these traits.


Biotic refers to living organisms and the factors that affect them, including their interactions with each other and their environment. It encompasses all living things, from microscopic organisms like bacteria and protozoa to large animals like elephants and whales. Biotic components of an ecosystem include plants, animals, fungi, bacteria, and other microorganisms.

Why are some objects considered alive and other objects considered non-living? In this video,  I cover the  characteristics of life which determine if an object is alive or not.