What does the endosymbiotic theory propose?

What does the endosymbiotic theory propose?

• A. Eukaryotic cells evolved from autogenous development within a single cell.
• B. Eukaryotic organelles arose from invaginations of the plasma membrane.
• C. Eukaryotic cells originated when certain prokaryotes entered into a symbiotic relationship with a host cell.
• D. DNA is inherited exclusively from the mother.

Answer: (C)

The endosymbiotic theory explains that eukaryotic cells originated when certain prokaryotes were taken inside a host cell and formed a mutualistic relationship, eventually becoming organelles such as mitochondria and chloroplasts. This idea is supported by evidence that these organelles have their own circular DNA, ribosomes similar to bacterial ribosomes, reproduce by binary fission, and possess double membranes consistent with the engulfing process. This combination of features fits best with the concept of ancient engulfment and partnership, rather than organelles forming solely by internal membrane folding or being inherited strictly from the mother.

The endosymbiotic theory explains that eukaryotic cells originated when certain prokaryotes were taken inside a host cell and formed a mutualistic relationship, eventually becoming organelles such as mitochondria and chloroplasts. This idea is supported by evidence that these organelles have their own circular DNA, ribosomes similar to bacterial ribosomes, reproduce by binary fission, and possess double membranes consistent with the engulfing process. This combination of features fits best with the concept of ancient engulfment and partnership, rather than organelles forming solely by internal membrane folding or being inherited strictly from the mother.