Question

What are the contrivances of self-pollination?

Answer 1

Hint: Pollination is the process of extracting pollen grains from the male component of a flower, the anther, and transferring them to the female part of the flower, the stigma. Pollen grains must be transported from the same species of flower in order for pollination to be successful.

Complete answer:
The major contrivances of self pollination is-
- Bisexuality.
- Homogamy.
- Cleistogamy.

Bisexuality- Each individual's flower has both male and female structures, combining both sexes in a single structure. This type of flower is known as perfect since it has both stamens and carpels. Androgynous, hermaphroditic, monoclinous, and synoecious are other synonyms for this condition.

Homogamy-The state of a flowering plant Plants with only one type of flower — one that produces both male and female components in the same flower – are known as monoecious. Heterogamy is the opposite of heterogamy. A condition in which both the anther and the stigmas mature at the same time in plants.

Pollination begins when pollen grains from the respective flowers land on the stigma and create a pollen tube the length of the style that joins the stigma and the ovary. The pollen grain begins transporting sperm cells from the grain to the ovary after the pollen tube is completed.

Cleistogamy is a sort of automatic self-pollination in which certain plants reproduce by means of non-opening, self-pollinating flowers. This habit is most common in the grass family and is most well known in peanuts, peas, and pansies.

Later, when the sperm cells reach the ovary and egg cells, the fertilisation process in plants will begin. With the use of pollination, the seed is then liberated from the parent plant, allowing it to grow into a plant and continue the reproductive cycle.

Types of Pollination- A plant having flower completely depend on the pollination method for reproduction, there are 2 types of pollination: Self Pollination, Cross-Pollination.

Self-pollination: Because only one flower is involved, it is referred to as primary pollination. Pollen grains fall directly from the anther into the stigma of the flower, resulting in self-pollination. Because the flower's sperm and egg cells share some genetic information, this procedure is simple and quick, resulting in a decrease in genetic variety.

Cross-pollination: It's a complicated method of pollination that allows pollen grains to be transferred from one flower's anther to the stigma of another. As various flowers share and integrate their genetic information to make unique offspring, this strategy increases genetic variety.

Note: In flowering plants, self-incompatibility is a common mechanism that prevents inbreeding and encourages outcrossing. One or more multi-allelic loci drive the self-incompatibility response, which is based on a sequence of complicated cellular interactions between self-incompatible pollen and pistil.