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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.
उत्तर
a) Those seeds that carry a living embryo and are capable of germinating into a seedling under appropriate conditions are termed as viable seeds.
(b) (i) Number of pollen grains required to form 200 seeds will be 200 only as each pollen grain carries to generative cells or male gametes and only one of the two are involved in zygote formation.
(ii) In total 400 gamete cells are required for production of 200 viable zygotes aleading to formation of 200 gauva seeds.
(c) Flow chart depicting the post pollination events:
APPEARS IN
संबंधित प्रश्न
Describe any two devices in a flowering plant which prevent both autogamy and geitonogamy.
Differentiate between outbreeding and outcrossing.
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 is the function of the part labelled '4'?
What is ‘double fertilization’? Describe it with the help of a neat and well-labeled diagram. Give its importance.
What is the significance of the dispersal of seeds? Give any two points.
Pollen tube was discovered by
Assertion: Sporopollenin preserves pollen in fossil deposits
Reason: Sporopollenin is resistant to physical and biological decomposition
Caruncle develops from
Name the cell which divides to form male nuclei.
Which of the following is the CORRECT sequence of events during double fertilization in Angiosperms?
The success of seed plants on land is mainly due to ______.
Due to which of the following reasons the pollen tube usually grows down towards the egg?
In angiosperms, for formation of which of the following triple fusion is necessary?
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.
In a fertilised embryo sac, the haploid, diploid, and triploid structures are ______.
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.
All the events from pollen deposition on the stigma until pollen tubes enter the ovules are together referred to as ______.
Name the part of gynoecium that determines the compatible nature of pollen.
In the figure given below label the following parts: male gametes, egg cell, polar nuclei, synergid and pollen tube
