Use your understanding of the nitrogen cycle to answer

The nitrogen cycle could not exist without nitrogen fixing microbes. These microorganisms are capable of transforming the atmospheric nitrogen in the form of fixed nitrogen. This form of nitrogen can be used by the plants. More than 90 per cent of the nitrogen are converted into usable form by the help of nitrogen fixing bacteria.There are basically two steps in nitrogen cycle. Nitrification and denitrification. The conversion of ammonia to nitrate is called nitrification and the conversion of nitrates into nitrogen is called Denitrification. The Rhizobium, Clostridium, some blue-green algae, Pseudomonas are some species of bacteria involved in Nitrogen Cycle.

Explanation:

Fungi contain many different microscopic organisms compared to regular plants, Fungi can be very poisonous compared to plant too and also a regular plant contains a cell wall where as Fungi don't. Most importantly plants use the process photosynthesis to make their own food, Fungi don't.