What are the characteristics of the first anaerobic cells? What does it mean that they were anaerobic?

Anaerobic" means "without oxygen metabolism." Most multicellular organisms have some cells, such as muscle cells, capable of temporary anaerobic metabolism. Other organisms, the facultative anaerobes, can survive temporarily in an anaerobic environment under special circumstances. True, or obligate anaerobic species must remain in an oxygen-free environment in order to survive.

Anaerobic means "living, active, occurring, or existing in the absence of free oxygen", as opposed to aerobic which means "living, active, or occurring only in the presence of oxygen." Anaerobic may also refer to: Anaerobic adhesive, a bonding agent that does not cure in the presence of air.

the index of refraction of the second medium is higher. i just took the test trust me !

b. lithosphere, asthenosphere, mesosphere   is the answer most likely