At which stage of pollen grain development are the male gametes formed?

In the male reproductive whorl of a flower,the archesporial cells are formed by . . . . . . .

Which part of the reproductive structure produces both enzymes and hormones?

Describe the location and function of the $Endothecium$ and $Tapetum$.

Consider the following statements and choose the correct answer from the given options.
$Statement \ 1$: Innermost layer of microsporangium is tapetum.
$Statement \ 2$: Cells of tapetum possess dense cytoplasm, more than one nucleus, and nourish the developing pollen grains.

Assertion: If pollen mother cells have $42$ chromosomes,the pollen has only $21$ chromosomes.
Reason: Pollens are formed after meiosis in pollen mother cells.