Which bacterium is responsible for converting ammonia into nitrites in the nitrogen cycle?
A. Nitrobacter
B. Rhizobium
C. Azotobacter
D. Nitrosomonas
Answer: Option D
Solution (By JKSSB Mock Tests)
Nitrification is a two-step aerobic process in the nitrogen cycle. First, ammonia (NH3) is oxidized to nitrites (NO2-) by bacteria like Nitrosomonas and Nitrosococcus. In the second step, nitrites are oxidized to nitrates (NO3-) by Nitrobacter. Rhizobium fixes nitrogen, and Azotobacter is a free-living nitrogen fixer.
Explanation:
Luster is a characteristic physical property of metals, but some non-metals also exhibit a shiny appearance. Iodine is a non-metal that forms dark purple, lustrous crystalline solids. Sulphur is dull yellow, phosphorus is white/red and waxy, and carbon (as graphite/coal) is generally dull.
Explanation:
In any electrochemical cell, the anode is defined as the electrode where oxidation (loss of electrons) takes place, and the cathode is where reduction (gain of electrons) occurs. In an electrolytic cell, the anode is positively charged, attracting anions which then lose electrons.
Explanation:
Ozone (O₃) is a powerful disinfectant that decomposes to O₂, leaving no residual taste or odor. However, it must be generated on-site and provides no lasting protection. Chlorine leaves residual.
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