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प्रश्न
Name the cell which divides to form male nuclei.
उत्तर
Double fertilization and triple fusion
S.G. Nawaschin and L.Guignard in 1898 and 1899, observed in Lilium and Fritillaria that both the male gametes released from a male gametophyte are involved in the fertilization. They fertilize two different components of the embryo sac. Since both the male gametes are involved in fertilization, the phenomenon is called double fertilization and is unique to angiosperms. One of the male gametes fuses with the egg nucleus (syngamy) to form Zygote.
The second gamete migrates to the central cell where it fuses with the polar nuclei or their fusion product, the secondary nucleus, and forms the primary endosperm nucleus (PEN).
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संबंधित प्रश्न
Describe any two devices in a flowering plant which prevent both autogamy and geitonogamy.
What are the advantages of the following in the flower to the plant concerned?
Protruding and easily movable anthers
Explain the pollination process in Salvia
What happens to the ovary post fertilization?
What is polyembryony? How it can commercially exploited.
Which of the following is the CORRECT sequence of events during double fertilization in Angiosperms?
From the following identify the fate of the male gametes discharged in the synergid.
In a breeding experiment, the selected male parent is diploid and the female parent is tetraploid. What will be the ploidy level of the endosperm that will develop after double fertilisation?
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.
In the figure given below label the following parts: male gametes, egg cell, polar nuclei, synergid and pollen tube