Can someone give me an explanation of endosymbiosis, in their own words?

Question

Please no plagarism. Your own thoughts on it would be nice.

Answer 1

endo = inner, sym = together and biosis = living

The word means exactly what the greek origin entails. In human biology, the cell is a perfect example of this. You have all the organelles (mitochondria, lysomes, etc) all living within the cell. So, the relationship that organelles have with the cell is endosymbiotic.

Answer 2

Symbiosis is the term used to describe different species that are adapted to be dependant on each other specifically. Depending on who is talking, this may include parasitism (which benefits only one of the creatures) or be contrasted with it.

Sometimes the term is prefixed to indicate HOW the symbiotes are living together. An ectosymbiote is living on its partner in a way that it might be scraped off without harming it (these include barnacles and digestive bacteria). An endosymbiote is living INSIDE its partner in some way (these might include certain organelles such as chloroplasts, nitrogen-fixing bacteria in root nodules, and some bioluminescent bacteria in various creatures).

Other words are sometimes affixed as well to indicate other things about the relationship. Obligate symbiotes, for example, MUST live with each other, while facultative symbiotes simply get a big advantage for doing so. In addition to parasitism (where one creature benefits at the expense of the other) there is also commensalism (where one benefits but the other doesn't suffer) and mutualism (where they both benefit).

Hope that helps!