What happen to haploid megaspores formed by megaspore mother cell in a...
Understanding Megaspores in Angiosperms
In angiospermic plants, the process of megasporogenesis leads to the formation of megaspores from the megaspore mother cell (megasporocyte). This process is crucial for the development of the female gametophyte, known as the embryo sac.
Formation of Megaspores
- The megaspore mother cell undergoes meiosis, producing four haploid megaspores.
- These megaspores are genetically distinct due to the process of meiosis.
Fate of Megaspores
- Out of the four megaspores formed, typically three degenerate.
- One megaspore survives and undergoes mitotic divisions.
Development of the Embryo Sac
- The surviving megaspore undergoes three mitotic divisions, resulting in an eight-nucleate structure.
- This structure develops into the embryo sac, which contains the egg cell, synergids, polar nuclei, and antipodal cells.
Significance of the Process
- The degeneration of three megaspores ensures that resources are concentrated on the development of a single, viable embryo sac.
- This strategy enhances the efficiency of fertilization and subsequent seed development.
Conclusion
Thus, the correct answer is option A: three megaspores degenerate, and one produces the embryo sac, which is essential for successful fertilization and seed formation in angiospermic plants.