1. Cellular Organization 2. Reproduction 3. Metabolism 4. Homeostasis 5. Heredity 6. Response to Stimuli 7. Growth and Development 8. Adaptation through Evolution

1. There are some certain points when discussing about living and non-living things. They are mostly specific on living things such as cellular organization, reproduction, metabolism, homeostasis, heredity, response to stimuli, growth and development and adaption through evolution. Things which have these characteristics are called as living things and things which haven’t are called as non-living things. On certain occasions we can identify living things that miss one or several characteristics from the list. For an example trees don’t show direct movements, just only the growth movements, neurons don’t reproduce, the animals that have non sexual reproductive system and the trees which are reproduced by propagation don’t show adaptations or evolutions.
Importantly, some non-living things too show one or several characteristics that defines life. For an example if we think about computer it’s a logical machine, it consumes electricity. So it shows metabolism, it control its’ temperature. That’s homeostasis. It responses to stimuli. Every day its’ storage memory grows bigger. So it shows the growth. If we think about a vehicle it shows clear movements, it needs fuel to run. So that’s metabolism. While driving wheels turn where ever we turn the steering wheel. So that’s a response to stimuli.
When we think about sun via nuclear reactions it gains energy. That’s metabolism.
Consider about water, it floats; actually a movement. So it’s a living characteristic.
2. Snail is a living organism while a rock isn’t. When we consider about a snail it shows all the characteristics. It has a well-organized cellular system including a nerve system, muscular system, urinary system, circulatory system etc. It has a reproductive system so snails reproduce their new generations. It shows metabolism. It eats and has a digestive system so it can digests the foods eaten. It shows respiration and it’s a great example for metabolism. Snails regulate the Calcium level and the PH of blood. So it’s homeostasis. It responses to stimuli, for an example if you touch a snail you can see it creeps in to its’ shell. Snail has a three staged life cycle. Hatchlings, sexually immature snails and the sexually mature snails. So it shows the growth and development.
But when we consider about a stone it shows no cellular organization, reproduction, metabolism, homeostasis and heredity, response to stimuli or adaptation. That’s why it’s called as a non-living thing.
But on some circumstances we can see the growth of stones, since it can combine with minerals and get bigger.

3. Tree is a living organism while the rock isn’t. Tree has a cellular organization including reproductive tissue, dermal tissue, ground/root tissue, vascular (xylem and phloem) tissue etc. Trees show metabolism, photosynthesis is the best example for that. Also trees respirate too. Trees control the water and O2 level in cells, so it’s homeostasis. Trees response to stimuli. They grow toward the sun light, when Mimosa pudica plant’s leaves are touched, it fell down just like sleeping. Trees show the growth and development until they die. Trees show adaptations. For an example, orchid plants have an adaptation to absorb water from air. Cactus has adopted to conserve water by having no leaves.
But when we consider about stones as above mentioned most of the time it has no characteristics of living.

4. Dog is a living organism while TV isn’t. Considering about a dog it shows well completed cellular organization. It has a nerve system, Urinary system, Skeletal and muscular system, circulatory system etc. It shows reproduction. Sexually there are male and female dogs for it.
Dogs clearly show metabolism. It eats, digests and has a digestive system for it. They gain energy by respiration which is a direct sign of metabolism. Dogs show homeostasis. Temperature, PH level, water balance and other requirements of the internal environment are regulated well in their bodies. We all know dogs response to stimuli and they show growth and development. Dogs have many adaptations such as they have a sharp awareness about the near sounds, movements and smells.
TV is classified as a non-living material as it shows no growth, cellular organization or heredity. But importantly it responses to stimuli. For an example if we want to change the volume or the channel of the TV, we just have to press a button. It responses according to the command of the button. Also TV generates sound automatically. It’s a significant sign of living. Electricity is the food for the TV. So it shows the metabolism. T.V. regulates its’ temperature by internal fans, so it shows homeostasis. So the TV shows some of the characteristics of living.
5. In ancient ages people used to think fire was alive even they worshiped fire thinking it’s a god. On some certain point someone can argue fire is living as it reproduces. If there’s something near fire usually it catches on fire. Especially fire grows. More fuel you add, the bigger it gets. It shows metabolism. Fire eats anything which can be burned. (wood, cloth, flesh, etc.) Would you believe if I say fire breathes. It needs oxygen for the combustion and fire stops if there isn’t any oxygen. So it’s a kind of breath, we can say. So relying on these facts it’s fair to argue Fire is living.