Pollen grain develops from . . . . . . of anther.

Which layer of the microsporangium helps in protection and dehiscence?

Development and formation of pollen grains in the anther of the stamen is known as:

$A$: In sporoderm,the pectocellulosic layer is surrounded by sporopollenin.
$R$: Exine is differentiated into outer ektexine and inner endexine.

What does the tapetum provide nourishment to?

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