Q. Nitrifying bacteria are :
(a) Autotrophs
(b) Chemoautotrophs
(c) Phototrophs
(d) Heterotrophs
Solution :
Correct option : B Chemosynthetic bacteria are organisms which obtain energy from the oxidation of inorganic molecule. Inorganic molecules act as a source of energy and get converted into organic substances. Inorganic molecules, such as ammonia, molecular hydrogen, sulphur, hydrogen sulphide and ferrous iron, are used to produce the organic compounds needed by the bacteria for their subsistence. Nitrifying bacteria is a chemosynthetic bacteria which obtain energy from the oxidation of inorganic molecule like ammonia into organic molecules like nitrites and then to nitrates by the process of biological oxidation. So, the correct answer is option B.