All organisms need energy to perform different functions, and the energy needed is typically obtained through atp. which bond in atp must be broken in order to release energy during cellular respiration?

ATP is the energy currency of the cell. The synthesis of ATP occurs during cellular respiration in the cell. This energy is used by cells to perform the different metabolic functions of the cell.  

The energy is stored in the terminal phosphoanhydride bonds. This bond is called a high energy bond and when this bond is broken down then this high energy is released in the environment and is used to perform the important functions of cells. After the breakage of the bond, ATP converts into ADP.

thermophiles, notice the prefix thermo.

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).