Biology Question.

Question

Many species of photosynthetic algae live inside the bodies of animals s as corals, sponges,and marine slugs. In symbiotic fashion, the photosynthetic algae or plant makes food for itself and the host, while the host animal builds and maintains a living space. How is this modern day example of an autotroph living with a heterotrop similar to and different from what was seen with the first Endosymbionts?

Answer 1

This is similar to when the ancestors of mitochondria began an endosymbiotic relationship with larger bacteria-like organisms. Another example would be the ancestors of the chloroplasts forming an endosymbiotic relationship with plant ancestors. http://www.fossilmuseum.net/Evolution/Endosymbiosis.htm

Answer 2

The examples are similar in that a smaller cell lives within host cells, but in the modern day example the algae are eukaryotes (with their own endosymbiotic chloroplasts and mitochondria living within them! Multiple layers of endosymbiosis!) living inside larger coral eukaryotic cells. The original symbionts were prokaryotes living inside larger prokaryotes. Here’s a good resource to read about this: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3372257/