During normal breathing, the brain is stimulated to breath with increasing acidity as a result of CO2 concentration from basic metabolic processes. The brain is quite selfish and only really wants to maintain it's pH which should be at a range of 7.3-7.45, and will not tolerate any decrease.
In patients who have a chronic respiratory disorder with things like COPD. The brain has become accustomed to excessive acidic content, and is now stimulated by the Hypoxic drive or by low oxygen content.
Bacteria and fungi carry out decompostion of plants and animals
c. cell wall, vacuole
Among the choices above, the two features that indicate that a cell is a plant cell is the cell wall and vacuole. The cell wall can only be found in plant cells. It is the rigid cell that surrounds the cell membrane. The vacuole of a plant cell and animal cell are way too different. The vacuole of an animal cell is usually more than one and small, even smaller that that of the plant cell. On the other hand, the vacuole of the plant cell is only one in fact a large one that takes up almost 90 percent of the volume of the cell
