What are the important characteristics of living organisms?

(N/A) The important characteristics of living organisms are:
$1$. Growth (increase in mass and number of individuals).
$2$. Reproduction (production of offspring).
$3$. Metabolism (biochemical reactions occurring inside the body).
$4$. Response to environmental stimuli (consciousness).
$5$. Ability to self-organize.
Detailed explanation:
- Growth: All living organisms grow. Increase in mass and increase in the number of individuals are twin characteristics of growth. In plants,growth by cell division occurs continuously throughout their life span,whereas in animals,it occurs only up to a certain age. Growth is not a defining property of living organisms because non-living objects (like mountains or boulders) also increase in mass by accumulation of material on the surface,whereas living organisms grow from inside.
- Reproduction: Living organisms produce offspring similar to themselves. While it is a characteristic of life,it is not a defining property because some organisms like worker bees,mules,and infertile human couples do not reproduce.
- Metabolism: The sum total of all chemical reactions occurring in a living body is metabolism. It is a defining feature of all living organisms without exception.
- Consciousness: The ability to sense the environment and respond to environmental stimuli is a defining property of living organisms.