Question

How did early eukaryotic cells benefit from the aerobic bacteria that took up residence within them? the aerobic bacteria helped protect the cell against predation?

Answer 1

If your choices are the following, then the correct answer is C:

a. The aerobic bacteria were able to capture the sunlight and generate sugars from it.

b. The aerobic bacteria helped protect the cell against desiccation.

c. The aerobic bacteria metabolized sugars and generated large amounts of ATP.

d. The aerobic bacteria helped protect the cell against predation.

This is actually the endosymbiotic theory of how we humans (and other organisms alike) have evolved to have mitochondria inside our cells. Evidence to support this is that mitochondria have their own DNA different from ours.

A can't be the answer because that is more related to plants. B and C are also wrong because they simply do not provide those functions.

Answer 2

The endosymbiotic theory states that aerobic bacteria took up residence inside these cells 2 billion years ago. These cells started producing oxygen for eukaryotic cells and are now known as mitochondria. The aerobic bacteria allowed these cells to be protected against some predators, as the cells could live in areas they once could not live in before.