I guess that is:
Within the capillaries of the lungs, gases are exchanged by diffusion; O2 diffuses from the alveolus to the bloodstream and CO2 diffuses from the bloodstream to the alveolus.
Answer:
amoeba
Explanation:
unicellular are the organism which have single cell.
Fermentation is a type of chemical process which enables heterotrophs to obtain energy without oxygen . Heterotrophs uses procedure of fermentatation to cultivate because in process of fermentation enzymes are the catalysts and they provide energy to heterotrophs
ALL animals make use of other animals and organisms for food. They are heterotrophic so they have to get energy elsewhere.
ALL animals are capable of motion at some stage of their lives.
Animals developed specialized cells and tissues that are advanced and complex.
And because all animals eat I would assume they all digest the food they ingest. Other than parasites who don't really digest their food.
Your answer would be cumulus clouds.