Carbonate groups contain a single carbon atom, and three oxygen atoms in a trigonal molecular geometry. The carbon atom has two single bonds to two oxygen atoms and a double bond to the third oxygen atom. Therefore, in addition to carbon, carbonate minerals contain oxygen. An example of a carbonate mineral is calcium carbonate, often found within rocks. 
        
             
        
        
        
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The sister chromatids are identical to one another and are attached to each other by proteins called cohesins. They are formed.
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Answer:
Nitrogen-fixing bacteria is capable pf transforming nitrogen present in the atmosphere into fixed nitrogen i.e. usable for plants.
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Answer:
they do not evolve, they are birds
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