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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
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 is the function of the pollen tube? Explain it with the help of a diagram.
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'?
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 ‘double fertilization’? Describe it with the help of a neat and well-labeled diagram. Give its importance.
What is a fruit?
What happens to the ovary post fertilization?
Pollen tube was discovered by
Syngamy results in the formation of ______.
In Haplopappus gracilis, number of chromosomes in cells of nucellus is 4. What will be the chromosome number in Primary endosperm cell?
Name the cell which divides to form male nuclei.
Through which route the pollen tube can enter the ovule?
Double fertilization was first discovered by Nawaschin (1898) in ______.
Double fertilisation was first discovered in 1898 by ______ in Fritillaria and Lilium.
Can an unfertilised, apomictic embryo sac give rise to a diploid embryo? If yes, then how?
What is the function of the two male gametes produced by each pollen grain in angiosperms?
Identity the part of embryo sac which takes part in formation of primary endosperm nucleus during fertlisation
Name the following:
A diploid nucleus in central cell of embryo sac in plants.
