The First Cells Were ____

Question

The first cells were ____.  
A) autotrophic
B) parasitic
C) anaerobic
D) aerobic
E) necrotic

Accepted Answer

The first cells were likely anaerobic, meaning they did not require oxygen to survive. This is supported by the fact that oxygen was not abundant in Earth's atmosphere until much later in history, and the earliest known fossils of cells are from anaerobic organisms. Autotrophic and parasitic behaviors likely developed later as evolution progressed. Necrotic is not a likely option as necrosis refers to the death of cells, not the creation of new ones. Aerobic metabolism, which requires oxygen, also evolved later.