Question

In human beings, air enters into the body through _________ and moves into
__________. In fishes, water enters into the body through _________ and the
dissolved oxygen diffuses into _________.

Answer 1

In human beings, air enters into the body through nostrils and moves into lungs. In fishes, water enters into the body through mouth and the dissolved oxygen diffuses into blood.

 The primary organ of the human respiratory system is lungs.

The air moves into lungs through nostrils and the oxygen from lungs is distributed throughout the body by red blood cells.

 In fishes the respiration takes place through grills.

The process of counter current flow, in which water and blood flow in opposite directions, maximizes the diffusion of oxygen.