Genus and species
The genus is always capitalized and the name is written in italics
luminosity and magnitude.
I guess
Molecule
Compound
Shell
Element
Planet earth is the only known region of the universe to host life and so the basic criteria for life is based on observations made here. For an entity to be considered a living organism it must contain DNA or some other means of storing genetic information. The second criteria is that it must have some way of extracting nutrients from its surroundings. The organism must be able to respond to environmental stimulus and last but not least it must be able to reproduce.