Tapetum is a part of
Male gametophyte
Female gametophyte
Ovary wall
Anther wall
$A$ : Growth of male gametophyte is completed over the female reproductive organ.
$R$ : $2-$celled stage of partial male gametophyte is developed in-situ.
$A$ : Each cell of the sporogenous tissue is capable of giving rise to a microspore tetrads.
$R$ : Most abundant microspore tetrads is the product of simultaneous cytokinesis.
The function of endothecium is
Mention about the viability of pollen grain.
Assertion : If pollen mother cells has $42$ chromosomes, the pollen has only $21$ chromosomes.
Reason : Pollens are formed after meiosis in pollen mother cell.