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प्रश्न
What is the function of the two male gametes produced by each pollen grain in angiosperms?
उत्तर
After entering one of the synergids, the pollen tube releases the two male gametes into the cytoplasm of the synergid. One of the male gametes moves towards the egg cell or oosphere and fuses with its nucleus, thus completing the syngamy. This results in the formation of a diploid cell, the zygote. The other male gamete moves towards the two polar nuclei located in the central cell and fuses with them to produce a triploid primary endosperm nucleus (PEN).
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संबंधित प्रश्न
Double fertilization is reported in plants of both, castor and groundnut. However, the mature seeds of groundnut are non-albuminous and castor are albuminous. Explain the post fertilization events that are responsible for it.
Match the items in Column A with those in Column B.
|
Column A |
Column B |
|
(a) Generative nucleus |
(i) Pollen tube |
|
(b) Germ pore |
(ii) Endosperm nucleus |
|
(c) Exine |
(iii) Testa |
|
(d) Secondary nucleus |
(iv) Fertilization |
|
(e) Integument |
(v) Male nuclei |
|
(f) Egg nucleus |
(vi) Rough |
What happens to the following after fertilization?
Ovules
What happens to the following after fertilization?
Calyx
Given ahead is a diagrammatic sketch of the sectional view of a germinating pollen grain. Study the same and then answer the question that follows:
Name the parts labelled 1, 2, 3, 4 and 5.
Given ahead is a diagrammatic sketch of the sectional view of a germinating pollen grain. Study the same and then answer the question that follows:
What happens to the part labelled '5' during the process?
What is ‘double fertilization’? Describe it with the help of a neat and well-labeled diagram. Give its importance.
Expand the following abbreviation IW.
Define fertilization.
What is a fruit?
Even though each pollen grain has 2 male gametes, why at least 20 pollen grains are required to fertilize 20 ovules in a particular carpel?
Which of the following happens during triple fusion?
The success of seed plants on land is mainly due to ______.
In angiosperms, for formation of which of the following triple fusion is necessary?
Identify the function of filiform apparatus.
In a fertilised embryo sac, the haploid, diploid, and triploid structures are ______.
Double fertilization is fusion of ______.
The female gametophyte of a typical dicot at the time of fertilisation is ______.
Find out the CORRECT sequence of events taking place in pollen - pistil interaction.
- Pollen tube enters one of the synergids and bursts to release male gametes.
- Pollen tube enters the ovule through the micropyle of the ovary.
- The pollen tube grows through the stigmatic tissue and then style.
- Pistil recognizes the correct pollen and accepts it.
Which is the triploid tissue in a fertilised ovule? How is the triploid condition achieved?
