In the human respiratory system, gas exchange occurs across the cells of the alveoli. Alveoli or an alveolus is the deepest part of the human respiratory system. This part of the respiratory system is a place where gas exchange between oxygen and carbon dioxide occurs from inhaled air to the blood cells<span>.</span>
Afferent nerve fibers carry signals from the somatic receptors to the posterior horn of the spinal cord or to the brainstem. So i beleive it is 4 but not too sure. Hope this helped a bit (:
Answer:
Explanation:
a chemical reaction that occurs when a substance reacts with oxygen, releasing energy in the form of heat and light.
Answer:
the number of big fish would increase
Explanation:
when theres a bunch of small fish, that is more food for the big fish ao the population of big fish will increase