Question

Which direction does carbon dioxide move during internal respiration?

a.from the blood into the lungs
b.from the lungs into the atmosphere
c.from the tissue cells into the blood
d.from the blood into the tissue cells
e.from the lungs into the blood

Answer 1

During internal respiration, carbon dioxide moves from the tissue cells into the blood. Option C is answer.

Step-by-step explanation:

Internal respiration refers to the exchange of gases that occurs at the cellular level within tissues. In this process, cells produce carbon dioxide (CO2) as a byproduct of cellular respiration. The generated CO2 diffuses out of the tissue cells into the bloodstream. Hemoglobin, a protein in red blood cells, binds with CO2, forming carbaminohemoglobin. The blood then carries the CO2 back to the lungs for eventual elimination during external respiration.

Options A, B, and E involve movements of carbon dioxide during external respiration or in the lung-air interface. Option D is related to the movement of oxygen, not carbon dioxide, during external respiration. Therefore, option C, "from the tissue cells into the blood," accurately describes the direction of carbon dioxide movement during internal respiration.

Option C is answer.