I would say it could be called the evolution of cyanobacteria, the ancestor of chloroplasts by being engulfed by a eukaryotic cell (the cyanobacteria). Chloroplasts conduct photosynthesis whereby chlorophyll captures the energy from sunlight.
Because they rely on their dense fur for insulation from the chilly ocean water, sea otters are particularly vulnerable to the detrimental effects of an oil spill. If a sea otter swims into an oil spill, its fur becomes soiled and loses its insulating qualities, allowing water to penetrate to its skin, causing hypothermia and ultimately, death.
hope this helps?
Dna replication occurs inside the nucleus :)