What is a pollen grain?

The whorl that produces male gametes is:

$A$ - Only some cells of the sporogenous tissue are capable of giving rise to microspore tetrad.
$R$ - The microspores are arranged in a cluster of four cells - the microspore tetrad.

Which is the outermost layer of the anther wall?

Which of the following parts is not a component of the stamen?

During meiosis in a pollen mother cell, the daughter cells are interconnected by cytoplasmic passages. The whole structure is called: