According to the endosymbiotic theory, why was it adaptive for the larger (host) cell to keep the engulfed cell alive, rather than digesting it as food?
A) The engulfed cell provided the host cell with adenosine triphosphate (ATP).
B) The engulfed cell provided the host cell with carbon dioxide.
C) The engulfed cell allowed the host cell to metabolise glucose.
D) The host cell was able to survive anaerobic conditions with the engulfed cell alive.

Question

Quizplus · Accepted Answer

The endosymbiotic theory proposes that the engulfed cell was a prokaryotic cell, such as a bacterium, that was eventually transformed into an organelle, such as a mitochondrion. Mitochondria produce ATP through aerobic respiration, which provides energy for the host cell. Therefore, it was adaptive for the host cell to keep the engulfed cell alive, as it provided a new source of energy in the form of ATP.

According to the Endosymbiotic Theory, Why Was It Adaptive for the Larger