Question

What sort of evidence have cell biologists discovered in support of the endosymbiosis theory of the origin of mitochondria and chloroplasts?

Answer 1

Biologist Lynn Marguilis first proposed the endosymbiotic theory in the year 1967.

This theory explains the evolution of eukaryotic cells from prokaryotic cells, that is, the anaerobic bacteria consumed aerobic bacteria and had formed a symbiotic relationship.It also explains the origin of important organelles like Mitochondria and Chloroplast.

The order in which organisms evolved in earth is an evidence for this, the fossil evidence shows that anerobic bacteria was followed by photosynthetic bacteria and then aerobic cells which can use the oxygen. So they aerobic and anaerobic bacteria would have had a symbiotic relationship after phagocytosis.

In her theory which mentions the origin of eukaryotic from prokaryotic the discovery of mitochondria and chloroplast with their own DNA different from the DNA in the nucleus was an evidence. Their DNA help in producing proteins and enzymes for their function and they also reproduce by replicating like bacterial cells.

Discovery of centrioles, structure and function also helped in gathering evidence for the endosymbiosis theory.

The susceptibility to antibiotics and ribosome structure (70S) are also other evidence for this theory.