There are two competing hypotheses put forth to explain the origin of eukaryotic cells. which of the following correctly states one of these hypotheses? question options:

ancient eukaryotic cells resembling archaeal cells first acquired symbiotic cyanobacteria that eventually took up permanent residence to become chloroplasts.
a symbiotic relationship between cyanobacteria and proteobacteria created the first ancient eukaryotic cell.
two types of prokaryotic cells, one of which was photosynthetic, fused to become the first ancient eukaryotic cell.
ancient eukaryotic cells resembling archaeal cells first acquired symbiotic bacteria that eventually took up permanent residence to become mitochondria.

The correct answer is: Ancient eukaryotic cells resembling archaeal cells first acquired symbiotic bacteria that eventually took up permanent residence to become mitochondria.

According to endosymbiotic theory mitochondria evolved from a small, autotrophic bacterium that was eaten (but not digested) by a heterotrophic simple eukaryotic cell. The relationship between two organisms became symbiotic (beneficial for both): eukaryotic cell provided protection and nutrients to the prokaryote, and in return, the prokaryotic cell provided energy through its respiratory cellular machinery (today we know it is electron transport chain). The relationship became permanent over time, they became dependent on each other.

Origin of chloroplast is similar: eukaryotic cell with mitochondria engulfed a photosynthetic cyanobacteruim.

The process by which large undissolved particles are brought into a cell being engulfed is known as phagocytosis. Phagocytosis is the process by which certain living cells called phagocytes ingest or engulf other cells or particles. The phagocyte may be a free-living one celled organisms, such as an amoeba, or one of the body cells, such as white blood cell.