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प्रश्न
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?
उत्तर
During germination of the pollen grain, part '5' (generative nucleus) present at the tip of the pollen tube divides into two sperm nuclei. The pollen tube enters one of the synergids and releases its two sperm nuclei. Of these, one sperm nucleus enters the egg cell and fuses with its nucleus, while the other sperm nucleus moves towards the two polar nuclei in the central cell and fuses with them.
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संबंधित प्रश्न
Read the following statement and answer the questions that follow :
"A guava fruit has 200 viable seeds."
(a) What are viable seeds?
(b) Write the total number of :
(i) Pollen grains (ii) Gametes
in producing 200 viable guava seeds.
c) Prepare a flow-chart to depict the post-pollination events leading to viable-seed production in a flowering plant.
Explain the events up to double fertilisation after the pollen tube enters one of the synergids in an ovule of an angiosperm.
During double fertilization second male gamete fuses with ___________.
What happens to the following after fertilization?
Ovules
What are the advantages of the following in the flower to the plant concerned?
Smooth and light pollen
What is ‘double fertilization’? Describe it with the help of a neat and well-labeled diagram. Give its importance.
Explain the pollination process in maize.
Pollen tube was discovered by
Assertion: Sporopollenin preserves pollen in fossil deposits
Reason: Sporopollenin is resistant to physical and biological decomposition
Pollen tube was discovered by
