Answer:
Present-day cells evolved from a common prokaryotic ancestor along three lines of descent, giving rise to archaebacteria, eubacteria, and eukaryotes.
Changed the composition of the oceans. Most of the iron was precipitated out by early life.
Changed the composition of the atmosphere.  Oxygen became available in abundance.
Explanation:
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Predation; Predation refers to the interaction between two organisms, a predator and a prey, where there is a flow of energy from one to another. The predator kills and consumes the prey. Predation provides energy to prolong the life of the predator and promote the reproduction of the predator, to the detriment of the prey (the organisms that is being consumed.
 
        
             
        
        
        
Answer:
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Explanation:
2
Percent composition by element
Element	Symbol	# of Atoms
Barium	Ba	1
Hydrogen	H	2
Oxygen	O	2