There are seven agreed upon characteristics of life. So, in order to be considered living, one must have every single one of these traits
Every living thing has DNA in cells. A single-celled organism has DNA in a cell.
Some way their structure is organized.
In humans, the heart is always (almost always) in the same place. The head is always on top of the neck, etc.
In order for a species to continue, it must reproduce.
Plant: Pollen and Ovule
Bacteria: Grow bigger, then split
All living things require energy. Some produce it, and some consume it, but they all require it.
Humans need food to eat, and they consume it through the process of metabolizing it.
All living things grow, or develop over time.
Bacteria- Get bigger, then split
Human- Get taller
Development- Some tapdoles > frogs, but they still develop over their lives
React to Stimuli
An organism must react to what's around them, or react to their impulse.
Sunflower faces the sun.
When you eat bad food, you might throw up.
Not only do they react, but sometimes they could even adapt to the conditions.
Bacteria becoming resistant to penicillin.