Microspore mother cells in anther are immediately enclosed by

Identify the structures marked $A$ to $F$ in the given diagram.

Which one of the following is resistant to enzyme action?

The process of microsporogenesis is known as:

The innermost wall layer of anther:

$P -$ This cell is big,has abundant food reserve and a large irregularly shaped nucleus.
$Q -$ This cell is small and floats in the cytoplasm of the vegetative cell. It is a spindle-shaped cell with dense cytoplasm and a nucleus.
$\quad\quad \quad P \quad \quad Q$