While it is very difficult to find fossils of the earliest cells, there are some probable early cell characteristics. Four of the five answers represent possible traits that the first cells may have had. Select the exception.

A) prokaryotic
B) autotroph
C) aerobic
D) anaerobic
E) heterotroph

It is unlikely that the earliest cells were aerobic, as aerobic respiration requires oxygen, which was not abundant in the early atmosphere. The other four characteristics, prokaryotic structure, autotrophic or heterotrophic metabolism, and anaerobic respiration are all possible traits of the earliest cells.