The life cycle of an angiosperm is given below. What are $P, Q$ and $R$?
$P \quad Q \quad R$

Choose the correct option for the given statements:
$(i)$ In western countries, a large number of pollen products in the form of syrups are available in the market.
$(ii)$ In rice, pollen grains lose viability within $30$ minutes of their release.
$(iii)$ Pollen grains are stored at $-196^{\circ}C$ (cryopreservation) in liquid nitrogen, not at room temperature, for future use.
$(iv)$ Pollen grains are released from the anther, not from the seeds of wheat and rice.

$A$: Growth of the male gametophyte is completed over the female reproductive organ.
$R$: The $2$-celled stage of the partial male gametophyte is developed in-situ.

Discuss with your teacher about:
$(i)$ haploid insects and lower plants where cell-division occurs,and
$(ii)$ some haploid cells in higher plants where cell-division does not occur.

How many spore mother cells are required to produce $64$ spores?

How many reduction divisions are necessary for the formation of $200$ grains of wheat?