Question

Match Column - I with Column - II.

	Column - I		Column - II
(a)	Nitrococcus	(i)	Denitrification
(b)	Rhizobium	(ii)	Conversion of ammonia to nitrite
(c)	Thiobacillus	(iii)	Conversion of nitrite to nitrate
(d)	Nitrobacter	(iv)	Conversion of atmospheric nitrogen to ammonia

Choose the correct answer from options given below.

• A. (a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)
• B. (a)-(ii), (b)-(iv), (c)-(i), (d)-(iii)
• C. (a)-(i), (b)-(ii), (c)-(iii), (d)-(iv)
• D. (a)-(iii), (b)-(i), (c)-(iv), (d)-(ii)

Answer 1

The Correct Option is B

The given question requires us to match organisms in Column I with their respective processes or roles in the nitrogen cycle mentioned in Column II. Here is the step-by-step explanation to arrive at the correct solution: 

1. Nitrococcus: This organism is primarily involved in the conversion of ammonia to nitrite, a crucial step in nitrification. Therefore, Nitrococcus matches with Column II (ii).
2. Rhizobium: This is a well-known nitrogen-fixing bacteria that converts atmospheric nitrogen to ammonia, aiding in biological nitrogen fixation. Thus, Rhizobium matches with Column II (iv).
3. Thiobacillus: This genus is associated with denitrification, which involves reducing nitrates to nitrogen gas or nitrous oxide, thus closing the nitrogen cycle. Thiobacillus matches with Column II (i).
4. Nitrobacter: This is another nitrifying bacterium responsible for the conversion of nitrite to nitrate, completing the nitrification process. Therefore, Nitrobacter aligns with Column II (iii).

Based on this explanation, the correct matching is:

(a)	Nitrococcus	(ii)	Conversion of ammonia to nitrite
(b)	Rhizobium	(iv)	Conversion of atmospheric nitrogen to ammonia
(c)	Thiobacillus	(i)	Denitrification
(d)	Nitrobacter	(iii)	Conversion of nitrite to nitrate

Hence, the correct answer is (a)-(ii), (b)-(iv), (c)-(i), (d)-(iii).