I believe the correct answer from the choices listed above is the third option. It is oxygen that is a necessary reactant for cellular respiration to occur. Cellular respiration, in a sense, is breaking down sugar in the presence of oxygen. Hope this answers the question.
spongy bone is found in the bones of the skull, sternum, vertebrae, the pelvis, the lining of the marrow cavity and the epiphysis.
The main structural difference between LDL and HDL is their compositions. Approximately 50% of the weight of an LDL particle is cholesterol and only 25% is protein. High-density lipoprotein particles, on the other hand, consist of 20% percent cholesterol by weight and 50% protein.
Potassium, carbon, sulfur, hydrogen, oxygen, nitrogen, calcium, magnesium, sodium, phosphorus, iron, zinc, silicon, fluorine, boron, cobalt, manganese, chromium, and some others