The process of microsporogenesis is known as:

Which is an incorrect statement?
$I$. Each cell of sporogenous tissue in anther is capable of giving rise to a microspore tetrad.
$II$. The pollen grain represents the male gametophyte.
$III$. Pollen grains are usually triangular and $10-15 \mu m$ in diameter.
$IV$. Sporopollenin is one of the most resistant organic materials,which can be destroyed only by strong acids and alkalis.

The tapetum is........

$A$ schematic illustration of the pollen grain is called

The innermost wall layer of the anther is the tapetum. What is the primary function of the tapetum?

Which organic substance can withstand extreme environmental conditions and cannot be degraded by any known enzyme?