The sun is the only star in the solar system. It is the center around which the known 8 planets and their planets revolves round giving an heliocentric system.
The solar system is but one of the systems in the milky-way galaxy.
The sun, our star provides energy for the whole solar system through a nuclear process occurring at its core.
Nuclear fusion is the source of energy that the sun possesses.
The process requires a very high activation energy in the presence of a high pressure and temperature to start up.
During nuclear fusion, small atomic nuclei combines into larger ones with the release of a huge amount of energy.
The energy released provides the needed heat to set up another fusion process. The process eventually degenerates into a series of chain reaction leading to the release of energy.
I think the correct answer from the choices listed above is option A. It is the alveoli that is composed of single layer <span>surrounded by a network of capillaries. These are used to allow oxygen and carbon dioxide to move from the lungs to the bloodstream.</span>
Total 18 ATP are produced because 9 FADH2 are converted into 9 ATP molecules and the earlier 9 ATP molecules are already present in the first b-oxidation process. The first Krebs cycle produces 27 NADH, 9 FADH2 and 9 ATP while on the other hand, the second Krebs cycle produces 9 ATP molecules from 9 FADH2 so total it produces 18 ATP molecules.
