ORIGIN OF ALGAE AND THEIR ROLE IN OCCURING LIFE 
                                           ON OUR PLANET 

      
        
       Origin of life on the Earth, tell us that during the time of making first bacteria, occured some problem that they cannot supply with sugar and other substances in the oceans. What happened in that time? In order to survive they succeed to make new way for synthesis which is based on using sun energy - photosynthesis. 
         Bacteria that develop process of photosynthesis (Cyanobacteria), produce its own sugar with help of carbon dioxide, water and sun energy, but gratitude for help of the pygment chlorophyll. They release oxygen, that gradually coming over the air. In fact, bacteria are they that change atmosphere on our planet Earth.  
         If there is area without oxygen, life could not be developed. There is different species of microalgae: blue-green (AFA and Spirulina), green (Chlorella i Scenedesmus), red (Dunaliella), brown, rose, violet, yellow and black microalgae. These algae are present in waters, on ground, on rocks and plants.  
         Blue-green algae are included in the group of procaryotes (small cells without nucleus, also without chloroplasts), they have the most primitive structure.