Cyanobacteria are primitive organisms where chloroplasts are believed to be originated. Now, with the theory of endosymbiosis, this suggests that these organelle from cyanobacteria was engulfed by other organisms which has helped them process light with the help of chloroplasts.
Primary succession can occur in essentially lifeless areas or regions in which the soil is incapable of sustaining life as a result of such factors as lava, sand dunes, or rocks left from a retreating glacier.
