Pollination – Class 12 | Chapter – 1 | Short Notes Series PDF

Pollination: Pollination is very important. It leads to the creation of new seeds that grow into new plants. Pollination occurs in several ways. People can transfer pollen from one flower to another, but most plants are pollinated without any help from people. Usually plants rely on animals or the wind to pollinate them.

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When animals such as bees, butterflies, moths, flies, and hummingbirds pollinate plants, it’s accidental. They are not trying to pollinate the plant. Usually they are at the plant to get food, the sticky pollen or a sweet nectar made at the base of the petals. When feeding, the animals accidentally rub against the stamens and get pollen stuck all over themselves. When they move to another flower to feed, some of the pollen can rub off onto this new plant’s stigma.

Process of Pollination

The process of pollination begins when the pollen grains from the respective flowers lands on the stigma and form a pollen tube with the style length, which connects both the stigma and ovary. After the completion of the pollen tube, the pollen grain starts transmitting sperm cells from the grain to the ovary.

Later the process of fertilization in plants will take place when the sperm cells will reach the ovary and egg cells. The seed is then released from the parent plant and making it able to grow into a plant and continue the reproductive cycle with the use of the pollination method.

Types of Pollination

  • Self Pollination
  • Cross-Pollination

Self Pollination

This type of pollination deals with only one flower and hence it is quite a basic type of pollination. When pollen grain from the male part of the flower (anther) falls directly on the stigma which is the female part of the same flower and fertilisation occurs, such type of pollination is called self-pollination. The plants that undergo self-pollination are referred to as self-pollinating plants. Some examples of self-pollinating plants are: wheat, apricot, rice, peanut etc.

Types of Self-Pollination:

  • Autogamy: It is a type of self-pollination where the transfer of pollen grains from the anther to the stigma takes place within the same flower. Coordinated opening, maturation and exposure of the anther and stigma are necessary for autogamy.
  • Geitonogamy: It is the type of self-pollination where the transfer of pollen grains from the anther to the stigma takes place between different flowers in the same plant. Though it seems like cross-pollination and takes place with the help of pollinators, both the gametes have the same plant as their origin.

Cross Pollination

In cross-pollination, the pollen from the anther of a flower on one plant is transferred to the stigma of the flower on another plant of the same species. Then, pollination occurs and a seed is able to form. This transfer happens when the pollen is moved by an insect, by water, or by the wind. This type of pollination requires that there are two plants of the same variety in the area. The flowers of plants that use cross-pollination are generally larger. The blooms also usually have a stigma that is taller than the stamens, which gives more of a chance for the pollen to spread to other flowers.

Types of Cross-Pollination:

  • Abiotic Cross-Pollination: Pollination occurring because of the movement of pollen grains from one flower to another due to agents like wind and rain.

  • Biotic Cross-Pollination: Pollination occurring because of the movement of pollen grains from one flower to another due to agents like animals, insects and birds.


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By Team Learning Mantras