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प्रश्न
Give a concise account of the steps involved in the fertilization of an angiosperm plant.
उत्तर
Steps involved in fertilization of angiospermic plant:
- Germination of pollen grain on stigma.
- Formation of pollen tube in stigma.
- Growth of pollen tube inside the style.
- The direction of the pollen tube towards the micropyle of the ovule.
- Entry of pollen tube into the synergid of embryo sac.
- Discharge of male gametes from the pollen tube.
- Fusion of male gamete with egg cell (syngamy)
- Fusion of second male gamete with polar nuclei (triple fusion/double)
संबंधित प्रश्न
What is triple fusion?
(a) Explain the events after pollination leading to the formation of a seed in angiosperms.
(b) Mention the ploidy levels of the cells of different parts of an albuminous seed.
Given ahead is a diagrammatic representation of the process of fertilization. Study the same and then answer the question that follows:
What happens to
i) Ovary
ii) Ovule after fertilisation
Given ahead is a diagrammatic representation of the process of fertilization. Study the same and then answer the question that follows:
What part does the stigma play in the process of fertilisation?
What is a fruit?
The question has four options. Choose the correct answer:
When only ovary forms fruits they are known as
Describe the process of double fertilization in angiosperms and add a note on its significance.
What is Mellitophily?
‘Pollination in Gymnosperms is different from Angiosperms’ – Give reasons.
By which of the following the megasporangium proper of an angiosperm ovule is represented?
In angiosperms, for formation of which of the following triple fusion is necessary?
Identify the function of filiform apparatus.
If the cells of the nucellus in the angiosperm ovule contain 24 chromosomes, then ____________ chromosomes will be present in the endosperm of a self-pollinated flower.
Double fertilization is characteristic of ______.
The female gametophyte of a typical dicot at the time of fertilisation is ______.
Double fertilisation was first discovered in 1898 by ______ in Fritillaria and Lilium.
Fusion of one of the male gametes with egg nucleus is referred to as ______.
Double fertilization is a distinctive feature of ______.
After fertilization, the seed coat of seeds develops from ______
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.
