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प्रश्न
Explain the post-pollination events leading to seed production in angiosperms.
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उत्तर
Pollination is the process of transfer of pollen grains from anther to stigma.
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When the pollen grains fall on the stigma, the pollen tube enters one of the synergids and releases two male gametes.
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One of the male gametes moves towards the egg cell and fuses with it to form zygote.
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The other male gamete fuses with the two polar nuclei and forms the primary endosperm nucleus. This is termed as triple fusion.
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After the triple fusion, the central cell becomes the primary endosperm cell (PEC).
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The primary endosperm nucleus gives rise to endosperm, while the zygote develops into embryo.
- Seeds are the fertilised ovules that are developed inside a fruit.
- The integuments of ovules harden to form the seed coat, and the micropyle facilitates the entry of oxygen and water into the seed.
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संबंधित प्रश्न
As a senior biology student you have been asked to demonstrate to the students of secondary level in your school, the procedure(s) that shall ensure cross-pollination in a hermaphrodite flower. List the different steps that you would suggest and provide reasons for each one of them.
The transfer of pollen grains from the anther to the stigma of the same or of another flower of the same kind is known as ______.
What is meant by pollination?
In bisexual flowers, maturation of gynoecium before androecium is known as ______.
For which of the following attractants and rewards are required?
Both chasmogamous and cleistogamous flowers are present in ______.
Anemophily type of pollination is found in ______.
Male and female flowers are present on different plants (dioecious) to ensure xenogamy, in ______.
Which one of these statements is incorrect?
The following statements seem to describe the water-pollinated submerged plants.
Identify the set of correct statements:
- The flowers of Vallisneria are colourful and produce nectar.
- The flowers of waterlily are not pollinated by water.
- In most of water-pollinated species, the pollen grains are protected from wetting.
- Pollen grains of some hydrophytes are long and ribbon like.
- In some hydrophytes, the pollen grains are carried passively inside water.
Choose the correct answer from the options given below:
