Question

In gymnosperms, pollination is exclusively by
A. Animals
B. Wind
C. Water
D. Insects

Answer 1

Hint: Pollination is the process that plays a major role in the reproduction of plants. It mainly helps in the transfer of pollen grains from the male to the female for the fertilization to take place. We all know that pollination can exclusively take place in gymnosperms as well as in angiosperms through various external agents.

Complete answer:
Pollination is a process in which pollen grains from the anther are transferred to the stigma either in the same flower or of a different flower. In 1761, it was first observed by Kolreuter.

In Gymnosperms, pollination is direct as pollen is transferred to the micropyle of the ovule directly by the wind. Anemophily is the mode of cross-pollination or transfer of pollen grains from a mature anther to the stigma of a pistil which is accomplished through the agency of wind.

Characteristic of anemophilous flower:
- Flowers are small and inconspicuous.
- Non- essential parts are present either absent or reduced.
- The flowers are colourless, odourless and nectarless.
- In the case of unisexual flowers, the male flowers are most abundant. In bisexual flowers, the stamens are generally numerous.
- Stamens have long filaments and are extrose and versatile.
- Anthers are versatile and stigmas are sticky, hairy or feathery.
- Pollen grains are light, small, dusty, smooth-walled, dry. They can be blown to a distance up to 1300 km. - Winged pollen grains of Pinus are found hundreds of kilometres away from the parents' plants.
- Anemophily is highly wasted as it is nondirectional.
- Pollen grains are produced in large amounts or numbers.

Anemophily is associated with the reduction in the number of ovules in each ovary as there is uncertainty about the reaching of the pollens on stigma. The pollen grains fly towards the female for the fertilization to take place.

Therefore the correct answer is option ‘B’.

Note: Consequently, the pollen grains are spread over large tracts so that even isolated plants get pollinated. In maize, the silky stigma of the cob catches pollen falling from male flowers. But a large number of pollen grains cause bronchial allergy or depression in many human beings. The phenomenon is also called hay fever. The allergy or fever is caused in India by pollens of Amaranthus spinosus, Chenopodium album, Ricinus communis etc.