Overall in science there are 8 characteristics that can be used to determine whether something is living or non-living. Living things are made of cells, have levels of organization, grow & develop, maintain homeostasis, process by metabolism, respond to stimuli, reproduce & evolve over time. Yes those are the eight characteristics of a living thing.
The first characteristic is that all living things are made of one or more cells. For instance living things are all multi-cellular, WE HUMANS, are multi-cellular. On the other hand though bacteria are unicellular but it’s also living. Multi-cellular organisms are made of many cells. The cell is the basic unit of life.
The second characteristic is all living things display organization. Different parts of a cell are organized to do different jobs. Different parts of a body are organized to do different jobs also. The levels of organization in biological systems begin with atoms and molecules and increase in complexity.
The next characteristic is all living things grow & develop. We humans are born as babies & grow into adults. Our body grows and changes, so do plants! They grow from root, to stem into big plants. The cells get bigger and organisms develop, become more complex and gain new characteristics over their life span.
The fourth characteristic is all living things respond to stimuli, they react to environmental changes. The reaction to a stimulus is a response. Organisms can sense stimuli in their environment and react appropriately. If an organism is unable to respond to harm it might not live long enough to reproduce. For example when you go to the doctor and they tap you on your knee, they are trying to test your reflexes.
The fifth characteristic is that all living things reproduce. Humans have kids and babies, then they reproduce and it goes on again forever! Animals mate and have their children too. Reproduction is important...