The microsporophyll of an angiosperm is known as.......

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 $\to$ ..........

Describe the internal structure of a microsporangium.

Given below are two statements.
Statement $I$: Generally,anthers in angiosperms are dithecous,having two pollen sacs in each lobe.
Statement $II$: Each sporangium produces pollens from sporogenous tissues by the process of sporogenesis.
In light of the above statements,select the correct answer from the options given below.

What is the typical diameter of a pollen grain?

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