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प्रश्न
Explain the events up to double fertilisation after the pollen tube enters one of the synergids in an ovule of an angiosperm.
उत्तर
The events which occur during double fertilization are:
Two male gametes are released by the pollen tube into the cytoplasm of synergid.
One of these male gametes moves towards the egg cell and fuses with the nucleus. This process is called syngamy and results in the formation of a diploid cell, zygote, which eventually forms an embryo.
The other male gamete moves towards the polar nuclei located in the central cell and fuses with them to form a triploid primary endosperm nucleus (PEN). This process is called triple fusion.
Since two types of fusion, syngamy and triple fusion, take place here, the phenomenon is called double fertilisation.
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संबंधित प्रश्न
'Formation of primary endosperm nucleus is called triple fusion'. Give reason
During double fertilization second male gamete fuses with ___________.
Give one word/term for the following:
When pollen grains of a flower reach the stigma of the same flower.
Explain the pollination process in Salvia
Size of pollen grain in Myosotis
Match the following
| I) | External fertilization | i) | pollen grain |
| II) | Androecium | ii) | anther wall |
|
III) |
Male gametophyte | iii) | algae |
| IV) | Primary parietal layer | iv) | stamens |
The correct order of haploid, diploid, and triploid structure in fertilized embryo sac is
Syngamy results in the formation of ______.
Male gametes in angiosperms are formed by the division of ______.
Define triple fusion.
‘Pollination in Gymnosperms is different from Angiosperms’ – Give reasons.
Write a short note on Heterostyly.
Identify the CORRECT statement with reference to cellular endosperm.
Double fertilization is fusion of ______.
The total number of nuclei involved in double fertilisation in angiospersm are ______.
Ovules fall off after fertilization.
All the events from pollen deposition on the stigma until pollen tubes enter the ovules are together referred to as ______.
In the diagram given below, show the path of a pollen tube from the pollen on the stigma into the embryo sac. Name the components of egg apparatus.
