What type of respiration takes place (i) in yeast, and (ii) in humans ?

"Respiration is a vital function of the body". Justify this statement.

What is the main difference between aerobic respiration and anaerobic respiration? Give one example of each.

Why is diffusion insufficient to meet the oxygen requirements of large multicellular organisms like humans?

What type of arrangement exists in the bodies of large animals to meet their oxygen requirements adequately?