In anther culture, the androgenic haploid plants are obtained from

$A$ : Restitutional nucleus can be observed in endothecium cells.
$R$ : Endothecium cells are usually triploid.

Because of it pollen grains are well preserved as fossils

Male gametophyte in angiosperms produces

Which one of the following statements is correct?

Which part of the reproductive structure produces both enzymes and hormones