15. Which of the following statement is WRONG?
    (1) Megasporocyte develops within the megasporangium of the ovule
    (2) Megasporocyte undergoes meiosis to produce four haploid megaspores
    (3) All the four megaspore undergo several mitotic division to form female gametophyte in most angiosperms
    (4) Female gametophyte is haploid

The incorrect statement among the given options about megaspore and female gametophyte development in plants is:

(3) All the four megaspores undergo several mitotic divisions to form female gametophyte in most angiosperms.

This is incorrect because, in most angiosperms, only one of the four megaspores (the functional megaspore) survives and undergoes mitotic divisions to form the female gametophyte; the other three megaspores degenerate.

The other statements are correct:

(1) Megasporocyte develops within the megasporangium of the ovule.

(2) Megasporocyte undergoes meiosis to produce four haploid megaspores.

(4) Female gametophyte is haploid.

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Introduction

The development of the female gametophyte in flowering plants follows a specific sequence starting from a diploid megasporocyte within the ovule’s megasporangium. The megasporocyte undergoes meiosis to produce four haploid megaspores, but only one megaspore typically survives to undergo mitotic divisions forming the multicellular, haploid female gametophyte or embryo sac. Understanding this developmental pathway is essential for grasping plant reproductive biology.

Correct Developmental Sequence

• The megasporocyte (also called megaspore mother cell) develops inside the megasporangium (nucellus tissue) of the ovule (Statement 1).

• The megasporocyte undergoes meiosis leading to the formation of four haploid megaspores (Statement 2).

• Typically, in angiosperms, one of the four megaspores (usually the chalazal-most) survives while the others degenerate during megaspore selection.

• The single functional megaspore proliferates through mitotic divisions to form the haploid female gametophyte or embryo sac (Statement 4).

Misconception in Statement 3

• It is a common misconception that all four megaspores develop into female gametophytes; in reality, only one develops while the others undergo programmed cell death.

• This developmental pattern is referred to as monosporic megasporogenesis, predominant in most angiosperms.

• Alternative patterns such as bisporic and tetrasporic occur but are less common and involve alterations in meiotic and mitotic divisions.

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Summary Table: Female Gametophyte Development Stages in Angiosperms

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Conclusion

The process of megasporogenesis in angiosperms involves meiosis of the megasporocyte forming four megaspores, with only one surviving to develop into the haploid female gametophyte. Therefore, the incorrect statement is that all four megaspores undergo mitosis to form gametophytes (Statement 3).

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