Assertion: Pollen mother cells (PMCs) are the precursor cells that give rise to pollen grains.
Reasoning:: Each PMC gives rise to two pollens.

Assertion (A) is true but Reason (R) is false .

The correct assertion is that pollen mother cells (PMCs) are the precursor cells that give rise to pollen grains, which are the male gametophytic cells. PMCs undergo meiosis, a specialized form of cell division, to produce four haploid cells known as microspores. Each microspore then undergoes further development to form a pollen grain.

However, the reasoning provided is incorrect. Each pollen mother cell (PMC) gives rise to four pollen grains, not two. During meiosis, the PMC undergoes two rounds of cell division, resulting in the production of four haploid microspores. Each of these microspores can develop into a pollen grain, which contains the male gametes necessary for fertilization.

To summarize, PMCs are indeed the first male gametophytic cells, but each PMC gives rise to four pollen grains, not two.