Even in absence of pollinating agents seed­ setting is assured in

Identify the set of correct statements:

$A$. The flowers of Vallisneria are colourful and produce nectar.

$B$. The flowers of water lily are not pollinated by water.

$C$. In most of water-pollinated species, the pollen grains are protected from wetting.

$D$. Pollen grains of some hydrophytes are long and ribbon like.

$E$. In some hydrophytes, the pollen grains are carried passively inside water.

Choose the correct answer from the options given below.

What are chasmogamous flowers? Can cross-pollination occur in cleistogamous flowers? Give reasons for your answer.

What type of pollination takes place in Vallisneria?

Given below are two statements :

Statement $I:$Cleistogamous flowers are invariably autogamous

Statement $II:$Cleistogamy is disadvantageous as there is no chance for cross pollination.

In the light of the above statements, choose the correct answer from the options given below :

Aquatic plant like water-hyacinth and water lily are pollinated by