Much of the pollution in the environment is a result of a. the use of too much water
.b. the use of landfills
. c. inadequate waste disposal
.d. newer pollution-control devices used at factories

Ten percent of energy is transferred from sun to the level indicated.

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.