Unisexuality of flowers prevents:

Self-incompatibility is a device for
$I$. Ensuring cross-pollination
$II$. Preventing self-pollination
$III$. Ensuring self-fertilisation
$IV$. Genetic control for self-fertilisation
Choose the correct statements from those given above.

...... prevents both autogamy and geitonogamy.

Which one of the following characteristics promotes cross-pollination?

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 plants do outbreeding devices prevent autogamy but not geitonogamy?