Sex-linked traits are more commonly expressed in males because: Females have 1 X chromosome
Males only have 1 X chromosome
Males have 2 X chromosomes
Females have 2 X chromosomes

Fungi is were it belongs

Mitochondria produce atp, a high energy compound. atp is used for all sorts of enzyme-mediated reactions, such as making proteins/nucleotides/etc, certain compounds cross the cell membrane, muscles move, etc.  without this source of energy, a cell will die. it will not be able to repair itself, defend against pathogens, etc.