Nitrogen Fixation

The objective is to correctly match functions given in List-I with organisms in List-II.

Let's analyze each function:

1. (A) Nitrogen fixation (bacterium): This process is a characteristic of certain bacteria known to fix atmospheric nitrogen. Azospirillum is a bacterium involved in this function.
2. (B) Phosphorous absorption: This is predominantly carried out by mycorrhizal fungi. Glomus is a mycorrhizal fungus that helps in phosphorus absorption for plants.
3. (C) Nitrogen fixation (cyanobacterium): Cyanobacteria, such as Oscillatoria, are known for fixing atmospheric nitrogen.
4. (D) Ethanol Production: This process is commonly associated with fermentation by yeast, specifically Saccharomyces.

Based on the above analysis, the correct matches are: (A)-(II), (B)-(III), (C)-(IV), (D)-(I)