- The development of anthers and male gametophytes is highly conserved among angiosperms. Following are some of the events associated with pollen development, in random order.
(a) Microsporogenesis in pollen sac to produce a tetrad.
(b) Asymmetric division forming immature pollen grain.
(c) Archespore division.
(d) Division of generative cell to form two sperm cells.
(e) Callose digestion to form free microsperes.
Which of the following option represent the correct series of events during pollen development?
(1) (a), (b), (c), (d), (e) (2) (c), (a), (e), (b), (d)
(3) (a), (c), (d), (b), (e) (4) (c), (e), (a), (b), (d)
The correct series of events during pollen development in plants is:
(2) (c), (a), (e), (b), (d)
Explanation of events in order:
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(c) Archespore division: The archespore cells divide to give rise to microspore mother cells (microsporocytes).
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(a) Microsporogenesis in pollen sac to produce a tetrad: The microsporocytes undergo meiosis, resulting in a tetrad of haploid microspores.
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(e) Callose digestion to form free microspores: The callose walls separating microspores in the tetrad are digested to free individual microspores.
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(b) Asymmetric division forming immature pollen grain: The free microspore undergoes an asymmetric mitotic division forming a larger vegetative cell and a smaller generative cell.
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(d) Division of generative cell to form two sperm cells: The generative cell divides mitotically to produce two sperm cells within the pollen grain.
Introduction
Pollen development, or microgametogenesis, in angiosperms is a well-organized and conserved sequence of events that leads to the formation of a mature male gametophyte capable of fertilization. This process begins with the division of archespore cells and proceeds through meiosis, cell wall remodeling, mitotic divisions, and eventually the production of two sperm cells.
Steps in Pollen Development
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Archespore division (c): Located in the pollen sac’s sporogenous tissue, the archespore cells divide mitotically to form pollen mother cells (microsporocytes).
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Microsporogenesis (a): Each microsporocyte undergoes meiosis producing four haploid microspores arranged in a tetrad.
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Callose digestion (e): Surrounding callose walls between microspores degrade enzymatically, releasing free microspores.
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Asymmetric mitotic division (b): The microspore undergoes pollen mitosis I, an asymmetric division producing a larger vegetative cell and a smaller generative cell.
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Generative cell division (d): The generative cell divides mitotically to produce two sperm cells, completing the mature pollen grain.
Significance
Each stage contributes to the proper formation of functional male gametophytes by ensuring genetic diversity through meiosis, structural transition via callose digestion, and polarity establishment through asymmetric division, culminating in the formation of motile sperm cells necessary for fertilization.
Summary Table: Pollen Development Sequence
| Step Number | Event Description |
|---|---|
| 1 | Archespore division |
| 2 | Microsporogenesis forming tetrads |
| 3 | Callose digestion freeing microspores |
| 4 | Asymmetric mitosis forming vegetative/generative cells |
| 5 | Generative cell division producing two sperm cells |
Conclusion
Pollen development follows the sequence of (c), (a), (e), (b), and (d) involving archespore divisions, meiosis, callose layer digestion, asymmetric mitosis, and subsequent generative cell division. This conserved developmental pattern leads to functional male gametes essential for plant reproduction.
2 Comments
Kajal
November 18, 2025C,A,E,B,D
Manisha choudhary
December 7, 2025Sabse pahle archespore m mitotic division hota h jo pollen sac m hota h
Is s microspore moter cell bnti h
Microsporogenesis k through tetrad bnta h
Callose digestion s free microspore bnte h tetrad s
Asymmetric divison s immature pollen grain bnte h
Ek vegitatve cell jo pollen tube bnati h ek germinative cell germinative cell further mitosis krti h two sperm cell bnati h
2nd option is correct answer (c), (a), (e), (b), (d)