Choose the correct option with respect to the function of the germ pore.

In wheat and rice, how long does the pollen grain remain viable after being released?

$A$: The generative cell comes to lie freely in the cytoplasm of the tube cell.
$R$: The cellulosic wall around the generative cell is dissolved.

$A$ - Due to meiosis in $MMC$,microspore tetrads are produced.
$R$ - $MMC$ is a large cell containing dense cytoplasm and a prominent nucleus.

Ubisch bodies are associated with the development of:

$P -$ This cell is big,has abundant food reserve and a large irregularly shaped nucleus.
$Q -$ This cell is small and floats in the cytoplasm of the vegetative cell. It is a spindle-shaped cell with dense cytoplasm and a nucleus.
$\quad\quad \quad P \quad \quad Q$