The answer is; medulla oblongata and pons.
In this region of the brain, there are chemoreceptors that can detect changes in the pH of the blood. These are called central chemoreceptor. There are also chemoreceptors in the arteries called peripheral chemoreceptors. When these chemoreceptors detect a drop in the blood PH (due to increased dissolved carbon dioxide in the blood), the depth and rate of breathing is increased in the lungs.
The answer is 300 joules of energy.
An energy pyramid is a presentation of the trophic levels in an ecosystem. Energy from the sun is transferred through the ecosystem by passing through various trophic levels. Roughly 10% of the energy is transferred from one trophic level to the next, thus preventing a large number of trophic levels.
