5. If two black dogs are crossed, seven black and two brown pups are produced.
a.
Which is the dominant allele?
b. Which is the recessive allele?
C.
What is the genotype of the parents?

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.

The anwser is the universe