Question

What is primary endosymbiosis? What evidence is there for this? What is secondary endosymbiosis? What kind of organisms are involved? What is the evidence for this theory?

Answer 1

Primary Endosymbiosis

Primary endosymbiosis is the process in which a eukaryote engulfs another living prokaryote. An organism may then use that organism to its advantage. If a eukaryotic cell engulfs a photosynthetic alga cell, the larger organism can then use the products of the alga and become an autotrophic organism.

Example:

when a cell long ago engulfed a photosynthetic Cyanobacterium. This bacterium would then become a plastid inside the cell and begin to share genetic material.

Secondary endosymbiosis

Secondary endosymbiosis is when a eukaryote cell engulfs another eukaryote cell that has undergone primary endosymbiosis.

This is all possible because of a double membrane that was made by the first layer of the endosymbiosis in primary endosymbiosis, and the membrane of the cell that was engulfed in secondary endosymbiosis forms the second layer. This is the reason that mitochondria and chloroplasts have a double phospolipid bi-layer.