Life is one of those things we often take for granted. But that may be because it’s just part of our existence every day.
It might seem simple to define life as well, but it can be quite complex. There are several things that scientists agree are essential to call something “alive”.
In order for an organism (a living thing) to be considered alive, it must:
- grow and develop (e.g., a seed to a flowering plant),
- be able to respond to environmental cues, like when you pull your arm away from heat,
- be able to reproduce or create offspring,
- be able to process food and turn it into energy, also known as metabolism,
- have ordered systems such as cellular structures,
- and be able to adapt
The study of life is known as biology. Everything that is alive (plants, animals, bacteria, protists, fungi) is being studied. Some biologists study how biological systems work, while others study how those systems go awry in disease.