Both mitiosis and meiosis begin with a diploid cell that contains replicated chromosomes. explain the main difference between these two prosesses and what type of daughter cells produced by each.

The main difference is that mitosis occurs in body cells and meiosis occurs in sex cells. Mitosis produces identical daughter cells and meiosis produces genetically different daughter cells.

Aneutral atom must have the same number of neutrons and protons? no, they must have the same number of protons and electrons

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.