Where are the microsporangia located?

Complete the following flow chart:
Pollen Mother cell $\to$ Pollen tetrad $\to$ Pollen grain $\to$ Vegetative cell
Pollen Mother cell $\to$ Pollen tetrad $\to$ Pollen grain $\to$ ..........

$A$ microspore mother cell forms

In angiosperms,the male gametophyte is shed at which stage?

The development of microsporangium occurs in .......

How many microspore tetrads are formed from one microspore mother cell?