The role an organism play in an ecosystem is its

Since a female is both xx chromosome and the male passes down the x chromosome, than the offspring would be female since a female is xx.

You need to give use the answers

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.