question_answer

Organisms changed earth?s surface from reducing to oxidizing status are :

A)  autotrophs                       

B)  heterotrophs

C)  chemotrophs                   

D)  heteroautotrophs

Correct Answer: D

Solution :

                 Earliest atmosphere on earth is of reducing nature due to presence of free hydrogen. Photoautotrophs are the organism which changed earth?s surface from reducing tooxidizing status by photosynthesis, when they consumed  and released. Chemotrophs are organism which synthesises organic food with the help of energy obtained from chemical reaction e.g., Certain bacteria like nitrifying bacteria. Heterotrophs are organism which obtained organic food from outside e.g., Parasitic, saprophitic organism.