Read the passage and answer the following question:

In flowering plants, the production of male and female gametes occurs within the pollen grain and embryo sac, respectively. Since both types of gametes are immobile, they require a mechanism to be brought together for fertilization to take place. Pollination is the process that serves this purpose. Pollination refers to the transfer of pollen grains, which are released from the anther to the stigma of a pistil. Flowering plants have developed various remarkable adaptations to accomplish pollination. They rely on external agents to facilitate the process of pollination.

Which of the following agent helps in the pollination of Vallisneria and Hydrilla ?

Water

The agent that helps in the pollination of Vallisneria and Hydrilla is water. Both Vallisneria and Hydrilla are aquatic plants that rely on water for their pollination process. In these plants, the male flowers release their pollen grains into the water, and the currents or water movement carry the pollen grains to the female flowers for fertilization. This mode of pollination, known as water pollination or hydrophily, is specifically adapted to the aquatic environment where these plants grow.

This type of pollination is called hydrophily. It is a relatively rare type of pollination, but it is well-suited for aquatic plants.

Here are some of the characteristics of hydrophily:

• The pollen grains are usually small and light, so they can be easily carried by water currents.
• The stigmas are usually long and sticky, so they can trap pollen grains that are carried by water.
• The flowers are often produced in clusters, which increases the chances of pollination.