Q. What is the endosymbiotic hypothesis about the origin of mitochondria? And what are the molecular facts that support the hypothesis? And To which other cellular organelles can the hypothesis also be applied?

It is presumed that mitochondria were primitive aerobic prokaryotes that were engulfed in mutualism by primitive anaerobic eukaryotes receiving protection from these beings and offering energy to them. This hypothesis is known as the endosymbiotic hypothesis on the origin of mitochondria.

The hypothesis is strengthened by some molecular evidence such as the fact that mitochondria have their protein synthesis machinery and own independent DNA, with their own ribosomes and RNA, and that they can self- replicate.

The endosymbiotic theory can be applied to chloroplasts too It is supposed that these organelles were primitive photosynthetic prokaryotes because they have their own DNA, ribosomes and RNA and they can self- replicate too.