Match List-I with List-II:
| List-I | List-II |
|---|---|
| Function | Organism |
| (A) Nitrogen fixation (bacterium) | (I) Saccharomyces |
| (B) Phosphorous absorption | (II) Azospirillum |
| (C) Nitrogen fixation (cyanobacterium) | (III) Glomus |
| (D) Ethanol Production | (IV) Oscillatoria |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (A)-(II), (B)-(III), (C)-(IV), (D)-(I)
(A) Nitrogen fixation (bacterium) — this matches (II) Azospirillum. It is a free-living nitrogen fixer and forms no root nodules.
(B) Phosphorous absorption — this matches (III) Glomus. The fungus forms mycorrhiza with plant roots.
(C) Nitrogen fixation (cyanobacterium) — this matches (IV) Oscillatoria. Cyanobacteria are autotrophic microbes, and many of them fix atmospheric nitrogen, e.g. Anabaena, Nostoc and Oscillatoria. They are an important biofertiliser in paddy fields.
(D) Ethanol Production — this matches (I) Saccharomyces. The yeast Saccharomyces cerevisiae ferments sugars into ethanol. It is used for commercial ethanol and in making alcoholic drinks.
Note: The original NTA paper printed Option (4) as “(A)-(IV), (B)-(III), (C)-(II), (D)-(I)”. It pairs the bacterium with Oscillatoria and the cyanobacterium with Azospirillum, so none of the printed options was correct; NTA gives Option (4) as the answer. For the benefit of students, Option (4) has been changed to “(A)-(II), (B)-(III), (C)-(IV), (D)-(I)”, the correct matching.
NCERT Extract:
Microbes as Biofertilisers – “Biofertilisers are organisms that enrich the nutrient quality of the soil. The main sources of biofertilisers are bacteria, fungi and cyanobacteria. You have studied about the nodules on the roots of leguminous plants formed by the symbiotic association of Rhizobium. These bacteria fix atmospheric nitrogen into organic forms, which is used by the plant as nutrient. Other bacteria can fix atmospheric nitrogen while free-living in the soil (examples Azospirillum and Azotobacter), thus enriching the nitrogen content of the soil. Fungi are also known to form symbiotic associations with plants (mycorrhiza). Many members of the genus Glomus form mycorrhiza. The fungal symbiont in these associations absorbs phosphorus from soil and passes it to the plant. … Cyanobacteria are autotrophic microbes widely distributed in aquatic and terrestrial environments many of which can fix atmospheric nitrogen, e.g. Anabaena, Nostoc, Oscillatoria, etc.”
Chemicals, Enzymes and other Bioactive Molecules – “… Yeast (Saccharomyces cerevisiae) is used for commercial production of ethanol.”