The evolution of the cellular respiration,which used oxygen to help harvest energy from organic molecules
Four cells and 10 chromosomes each. Before going through meiosis ii it has to go through meiosis i (homologous chromosomes separate) first to form two cells. Then both cells goes through meiosis ii (sister chromatids separate) to form two cells each. Therefore 4 cells.<span />
Mushu is a definitely answer
The potential energy in food is what we call a Calorie, which (note the capitalization) is actually a kiloCalorie (1000 calories). Just pick any food high in calories; fats and oils are very calorie dense.