Prokaryotes are the Earth`s firs living things. This are the simplest life forms exhibiting ( showing ) cellular structures. They exist in 2 major forms: - Eubacteria ( most of the common bacteria that are found everywhere ), - Archaebacteria ( ancient bacteria that live in very extreme conditions ). Answer: Prokaryotes.
Possible causes of hypoxia include too little oxygen in the atmosphere. getting very cold too little oxygen in the atmosphere obstruction of the esophagus taking several rapid deep breaths
