What does the endosymbiont
theory propose as the origin
for mitochondria and
chloroplasts? Explain.
Mitochondria are the cell organelle. It is usually termed as power house of the cell because it generates the power of ATP and all energy sources. Mitochondria seem to present in both prokaryotes and eukaryotes.
Endosymbiotic theory of origin of eukaryotic cells postulates that, eukaryotic cells are product of symbiotic incorporation of proto-eukaryotic cells and prokaryotic cells i.e. mitochondria evolved from an aerobic bacterium (Rickettsias) and chloroplasts of plants and red algae evolved from Cyanobacterium.
About 4 billion years ago, the primitive cells possessed three modes of nutrition such as photosynthesis, invagination of food particles or absorption of freely floating organic molecules. According to the theory, incorporation of cells which had capability of aerobic respiration and cells that invaginate the food occurred. These symbiotic cells had the capacity of aerobic respiration.
The theory for evolution of mitochondria holds that the mitochondrion evolved from a small autotrophic bacterium which was engulfed by a primitive heterotrophic eukaryote. This eukaryotic cell had arisen when an anaerobic prokaryote lost its cell wall.
Step by step
Solved in 3 steps
