Pollens have two prominent walls which are ... $A$... and ... $B$ .... Here $A$ and $B$ refers to
$A-Intine\; B-Protein coat$
$A-Exine\; B-Intine$
$A-Sporopollenin\; B-Intine$
$A-Sporopollenin \;B-Exine$
In monocots, male gametophyte is
The process of formation of microspores from a pollen mother cell is called
The cell that divides to form two male nuclei in angiosperms is