In how many stages does sexual reproduction occur in fungi?

$A$ type of life cycle in which plasmogamy,karyogamy,and haploidization take place,but not at a specific stage in the life cycle of an organism,is called:

$A$: Sexual spores in pink mould are meiospores produced endogenously.
$R$: They develop flask-shaped fruiting bodies in their sexual life cycle.

Mycology $(Mycetology)$ is a branch which deals with the study of

$A$ cell wall containing chitin is found in .........

Describe the reproduction of fungus.