What is the transport of O2 from the outside air to tissue cells and the transport of CO2 from tissue cells to the outside known as?

Respiration process

Explanation:

Respiration is simply defined as the biochemical process where the body cells derive their energy from the combination of O₂ and food molecules, and in return liberates CO₂, along with some amount of H₂O and energy. This process elaborates on how the tissue cells help in shifting the O₂ from the exterior air into the cells and in return allows the CO₂ to be released outside.

This process is highly essential for an organism to survive. An organism cannot survive without carrying out this process.

what are the two models

explanation:

there is none because earth is stationary and flat.