In some plants,the style is shorter,while in others,it is longer than the stamens. This condition is called:

Match the following contrivances from Column-$I$ with their examples in Column-$II$.

Column-$I$	Column-$II$
$i$. Protandry	$a$. Calotropis
$ii$. Prepotency	$b$. Tobacco
$iii$. Self sterility	$c$. Sunflower
$iv$. Herkogamy	$d$. Apple

The maturation of male (anthers) and female (stigma) reproductive structures at different times in the same flower (in order to reduce the possibility of self-pollination) is called:

In which of the following mechanisms is there a physical barrier between the stigma and the anther in bisexual flowers?

Explain what are outbreeding devices. Give its importance.

Which process is not prevented in maize?