Early said that mitochondria was evolved from their ancestral in an ancestral eucaryotic cell. A bacterium was engulfed by the ancestral eucaryotic cell, but the single-layered membrane bacterium manage to escape the digestion and was evolved through symbiosis with the engulfing cell and its progeny. The single-layered membrane bacterium was evolved to become double membrane mitochondria and the division occur which then producing a newly mitochondria.
The same process occur in the evolvement of chloroplast except that, it is occur by the continuation of the early eucaryotic cell, not ancestral anymore. The early eucaryotic cell contain mitochondria which engulfed the photosynthetic bacterium that was believed to be cynobacteria. The bacterium single layer membrane was then evolved to the double membrane of chloroplast.
Of course the process look fix in the sequence, but I still have the problem on understanding this process. Actually, the story of the evolvement of the mitochondria and the chloroplast above were to explain why the organelles have their own genome. However, there are still questions that lingering around my head. I’m is a person with difficult understanding. Please forgive me ^_^.
The question that I’m curious about are :
Thus this process of evolvement occur in human cell? In our ancestor cell? Or is it only just evolve in the other eucaryotes cell beside human cells? If not, how can our ancestor generate their energy from one single eucaryotic cell without mitochondria because the function of the mitochondria is to generate ATP for our body. Also in plant, because plant have mitochondria and chloroplast. The chloroplast is for the cell pigment and to produce food in the plant. Do our ancestor lived without mitochondria and the plant lived without chloroplast first before the evolvement of the mitochondria and chloroplast to occur? If that so, how can they live without generating energy for their daily life. Do we, human, evolve from the single eucaryotic cell before they engulf the bacteria and made it as mitochondria? From single cell———–>human with complex metabolism, does this really occur? But what about Charles Darwin said in its book, Charles Darwin‘s On the Origin of Species.