One of the major components of the cell wall of most fungi is

The edible part of a mushroom is ..........

Provide definitions/explanations for the following terms:
$(1)$ Heterocysts
$(2)$ Conidiophores

Plant diseases caused by $Ustilago$ are called smuts because ......

Basidiomycetes include ..........

There is a myth that immediately after heavy rains in forests, mushrooms appear in large numbers and form a very large ring or circle, which may be several metres in diameter. These are called as "fairy rings". Can you explain this phenomenon of fairy rings in biological terms? Discuss the mycelial structure in $Agaricus$ and its soil-borne nature.