Which part of the respiratory system does the transition from bulk flow of air to diffusion of individual gases occur?

Wht happens as electrons in the electron transport chain release their energy

Sea stars, sea urchins, sand dollars, and brittle stars are all memeber of a group, what is the common name of the group they are all in

What happens during interphase? (1)the nucleus grows to its full size. (2)the cell grows to its full size. (3)the nucleus divides into two nuclei. (4)the cell divides into two cells.