C. a rise in blood carbon dioxide concentration
Explanation:
Negative feed back mechanism refers to the control mechanism in which a product of a particular pathway controls the switch on and switch off of that particular pathway.
Since breathing increases the blood oxygen concentration and lowers carbon dioxide concentration and pH. The sensors that regulate the breathing should respond to oxygen concentration as the carbon dioxide is the by-product of respiration and is responsible for increasing blood pH. Thus increased Carbon dioxide levels in blood is the only factor which will trigger breathing.
Part of an organism, a nucleotide is a part
Survival I think (sorry if im wrong)
Answer:
Option A
Explanation:
Most of the human economic systems if not all operate with the human natural systems. Human economic system and natural systems almost dependent on one another in that they are linked by a network of interconnected processes; for example, human economic activity depend on natural, including a maintained system of primary productivity such as forests and agriculture etc.
You will notice that a plant cell has a cell wall, whereas animal cells do not have a cell wall.
