What is secondary endosymbiosis?
1 Answer
It is when a red or green algae is engulfed in another organism.
Explanation:
Primary chloroplast endosymbiosis is that photosynthetic cyanobacteria was engulfed in non-photosynthetic eukaryotic cell. That is how red and green algae were formed. Secondary endosymbiosis is, that this already photosynthetic eukaryotic cell became engulfed in another cell. The seaweed was formed this way.
Secondary endosymbiotic organisms can have three or even more membranes on chloroplasts and they can even contain residue of cell nucleus - nucleomorph. Those structures are residues of the engulfed primary endosymbiotic organism.
Secondary endosymbiotic organisms are Haptophyta, Dinophyta, Cryptophyta, Bacillariophyceae, Phaeophyceae, Xantophyceae, Chrysophyceae, and Dictyochophyceae.
