AP BIOLOGY

Detailed explanation-1: -They absorb oxygen from the surrounding air or water and give out carbon dioxide through plasma membrane by diffusion.

Detailed explanation-2: -The respiratory system is the organ system animals use to bring in oxygen and get rid of carbon dioxide. We call the process of bringing in oxygen and releasing carbon dioxide breathing.

Detailed explanation-3: -Oxygenated air, taken in during inhalation, diffuses across the surface of the lungs into the bloodstream, and carbon dioxide diffuses from the blood into the lungs and expelled during exhalation.

Detailed explanation-4: -In mammals, including humans, air enters the body through the nose and mouth, and moves into the lungs. Once in the lungs, oxygen from air passes through the moist interior of the lungs and is dissolved into the bloodstream. The heart pumps oxygenated blood to the rest of the body.

Detailed explanation-5: -When breathing in, the air is pumped into the organs of the respiratory system (e.g. lungs). Delicate blood vessels extract the oxygen from the air. The blood helps to transport the oxygen to the cells and tissue (exception: tracheal breathing) to be “processed” there.