Biology of life

Long before our time, there was question of how things are born. First answer was they come from trash and garbage and are self-born. This mindset was overturned century or two ago.

Now we know that life is "given" by parental organism for each living kind in our knowledge.

Now, let's start with what we consider living being. From simplest to more complex we can start with viruses. Some take them as living organism, others argue that they are not technically alive, because they can't procreate themselves. that's one of traits that all beings must have from some scientific point of view. Others talk about them as noncellular organismes.

Everything else we know are cellular organismes. They are made of 3 main branches. Specifically Archea, Bacteria and Eukaryotes. We believe that Eukaryotes came to being by ingestion of bacterial cell into archeatic cell. we call this event endosymbioses. it happened twice on base level, as for what we know now. First was mitochondria, cell organelle responsible for burning organic compounds with oxygen to make ATP. You can imagine it as cell's basic energetic unit or currency. It's need for most of things in cell. Other organelle is chloroplast, organelle responsible for creating organic compounds from atmospherical carbon dioxide and water.