Question

Pollination by water occurs in
A. Ceratophyllum
B. Zostera
C. Lemna
D. Both A and B

Answer 1

Hint: Pollination is a system of transferring pollen from a male part of a plant to a female part of a plant, which causes fertilization and the production of seeds. Most often this process takes place through the agency of an animal or by the wind or by through the water.

Complete answer:
Pollination is a process of transferring pollen grains and transfer of pollen takes place from the anther which is the male reproductive part of a flower to the stigma or the female reproductive part of a flower. Plants produce their new breed by making seeds that contain the genetic information to produce a new plant. This pollination is the process of reproduction as well as fertilisation when the pollen grains are transferred from the individuals of the same species.
The carrier of the pollen grains referred to as pollinating agents and the example of pollinating agents are animals such as insects, birds, and bats. Water, wind also acts as pollinating agents and even plants themselves act as a pollinating agent when pollination takes place within a closed flower. Pollination often occurs within a species.
The pollination is done by water is known as hydrophily where the flow of water is used to distribute the pollen grains and, in some cases, sometimes whole anthers are transported by water. This transport can occur across the surface of the water to carry dry pollen from one flower to another. Pollination by the agency of water is quite rare in flowering plants.
In Lemna, the pollination takes place through the agency of gastropods or snails which is known as malacophily. Ceratophyllum and Zostera are both aquatic plants. Zostera is fully submerged in marine water with long, elongated, and needle-like pollen grains and this pollen flows below the surface of the water, and pollination takes place. In the case of Ceratophyllum, it is submerged in freshwater. In this plant female flowers come in contact with the pollen grains released from the male flower and pollination takes place underwater. Thus, Ceratophyllum and Zostera both show the pollination by water.

Therefore, the most correct and appropriate option is option D.

Note: When pollen grain is transported from the male anther to the female stigma, this process is called pollination. And the pollen grain carried out by the animals like insects, birds, and bats. Wind and water also transport pollen. Pollination by water is when water distributes the pollen and its examples are Ceratophyllum and Zostera.