Members of which plant family, pollen grains maintain viability for months ?

Assertion : Pollen mother cells $(PMCs)$ are the first male gametophytic cells.
Reason : Each $PMC$ gives rise to two pollens.

Male gametophyte in angiosperms produces

Pollens have two prominent walls which are … $A$… and … $B$ …. Here $A$ and $B$ refers to

After demonstration of totipotency, a botanist wishes to produce identical plants from an angiosperm by tissue culture. The parts or tissues which are likely to yield haploid embryos are