Sexual Reproduction in Flowering Plants MCQs

In a corn cob, the ears or tassels seen waving in the wind are nothing but the stigma and style which wave in the wind to trap pollen grains.

Some examples of water pollinated plants are Vallisneria and Hydrilla which grow in fresh water. Zostera is a marine seagrass.

In a majority of aquatic plants such as water hyacinth and water lily, the flowers emerge above the level of water and are pollinated by insects or wind as in most land plants.

Pollen grains in many such species (seagrasses) are long, ribbon like and they are carried passively inside the water.

In some species floral rewards are in providing safe places to lay eggs; an example is that of the tallest flower of Amorphophallus.

A relationship exists between a species of moth and the plant Yucca where both species cannot complete their life cycles without each other. The moth deposits eggs in the locule of the ovary.

Continued self-pollination results in inbreeding depression. Plants have developed devices to discourage self-pollination.

In several species such as papaya, male and female flowers are present on different plants (dioecy). This condition prevents both autogamy and geitonogamy.

The other male gamete moves towards the two polar nuclei located in the central cell and fuses with them to produce a triploid primary endosperm nucleus (PEN).

Since this process involves the fusion of three haploid nuclei (one male gamete and two polar nuclei), it is termed triple fusion.