Question

Pollen grains of rice and wheat lose their viability in minutes of their release.

Answer 1

Pollen Viability
It is the ability of the pollen grain to perform its function of delivering male gametes to embryo sac without getting degraded. It tells how long a pollen can survive or remain active and take part in reproduction.

Factors affecting pollen viability
Tapetum that nourishes the microspore mother cell
Plant species in question
Prevailing temperature and humidity

Viability of pollen grains of rice and wheat
Pollen grains of rice and wheat lose their viability within 30 minutes of their release.

Final answer
(a) 30