How many meiotic and mitotic divisions need to occur for the development of a mature female gametophyte from the megaspore mother cell in an angiosperm plant?

Question

Question

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NEET 2025 Official Paper (Held On: 04 May, 2025)

Answer 1

The correct answer is 1 Meiosis and 3 Mitosis

Concept:

In angiosperms, female gametophyte development begins with the differentiation of the megaspore mother cell (MMC) within the ovule. The MMC undergoes meiosis to produce a linear tetrad of haploid megaspores.
Out of the four megaspores formed, typically only one survives, while the other three degenerate. This surviving megaspore develops into the mature female gametophyte (embryo sac) through a series of mitotic divisions.
The mature female gametophyte (embryo sac) contains seven cells arranged in three groups: one egg cell, two synergids, three antipodal cells, and a central cell with two polar nuclei.

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Explanation:

Step 1: Meiosis - The megaspore mother cell undergoes a single meiotic division to produce four haploid megaspores. Out of these, only one remains functional, and the other three degenerate.
Step 2: Mitosis - The functional megaspore undergoes three rounds of mitotic divisions, resulting in eight nuclei within a single cell. These nuclei are then arranged into seven cells, forming the mature female gametophyte (embryo sac).

Thus, the process involves one meiosis followed by three mitotic divisions.