The pollen viability period of rice and pea respectively, is
$30\; minutes$ and several months
Several months and $30\; minutes$
Few days and few months
Few days in both the cases
Germination of pollen grain on the stigma is
In flowering plants meiosis occurs at the time of
$A$ typical angiosperm anther is _________ and _________.
An organic substance that can withstand environmental extremes and cannot be degraded by any enzyme is
Which one of the following is resistant to enzyme action?