Answer:
Oxygen and pyruvate.
Explanation:
The krebs cycle is a stage of cellular respiration and occurs in aerobic organisms. In this case, we can say that the Krebs Cycle only occurs in the presence of oxygen, being essential for the completion of cell respiration.
The Krebs cycle only occurs after the completion of glycolysis, as it needs to be initiated by pyruvate, which is a molecule resulting from glycolysis. In this case, in addition to oxygen, the presence of pyruvate is essential for the krebs cycle to occur.
Radiation is responsible for the greatest loss of energy.
Sediment - rock that has formed from sediment deposited by water or air
Deposition - the geological process in which sediments, soil and rocks are added to a landform or land mass
Environment - the surroundings or conditions in which a person, animal, or plant lives or operates
