Although the candidates are selected instead of elected, the process has to follow strict standards. 1. The candidates have to be always in the political system.
1 An example of mettle is a soldier's bravery.  An example of mettle is a person who has spirit and courage.
Methanogenesis is a process where microorganisms produce methane from organic sources; Methanogens are the microorganisms involved in this process. Methane digestion is another important process where methane is utilized by microorganisms known as methanotrophs. Thus, the key difference between methanogens and methanotrophs is that methanogens produce methane whereas methanotrophs utilize methane.