Answer:
Phosphorus cycles between living things and the soil.
Plants absorb phosphates from the soil and turn them into organic compounds through assimilation.
Animals eat plants and pass the phosphorus through the food chain from one animal to the other.
An animal dies and decomposes, returning the phosphorus to the soil.
Explanation:
Answer:
C. the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing.
Explanation:
The central chemoreceptors are located near the medulla inside the blood-brain barrier. When CO2 in cerebrospinal fluid increases, pH of the fluid lower (because CO2 becomes hydrated to carbonic acid). Change in pH stimulates the central chemoreceptors to activate respiratory centers which will increase the respiratory rate and depth of breathing.
I think that the bright light would be the "stimulus" and the pupil constricting would be the "response".