Honestly? i really dont think there is one. We all just exist to die. We are all part of a machine. Nothing ever TRULY has meaning. If something is important it eventually wont be. Like, for example, say you just had a life changing surgery, it saved your life! Well it really wont matter because eventually, you will die anyway. I say to not take life to seriously, do whatever the he11 you want to do. Wanna get a tattoo? DO IT! It's gonna fade away eventually. You can't see a tattoo on a corpse right? Wanna save puppies from fires and rescue orphans? Whatever, weird flex but WHATEVER. What i'm
trying to say basically is, there is no meaning to life, so make the most of it before you don't have a life to give meaning to.
Cells make up the smallest level of a living organism such as yourself and other living things. The cellular level of an organism is where the metabolic processes occur that keep the organism alive. That is why the cell is called the fundamental unit of life.