How many meiotic and mitotic divisions need tooccur for the development of

How many meiotic and mitotic divisions need tooccur for the development of a mature femalegametophyte from the megaspore mother cell in anangiosperm plant?

Answer

Question:

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

Explanation:

1. Megasporogenesis:

• A single megaspore mother cell (MMC) is located in the micropylar region of the nucellus.
• The MMC undergoes one meiotic division (Meiosis I and II), producing four haploid megaspores.
• Only one megaspore remains functional, and the other three degenerate.

2. Development of the Female Gametophyte (Embryo Sac):

• The functional megaspore undergoes three mitotic divisions:
  • First mitosis → 2 nuclei.
  • Second mitosis → 4 nuclei.
  • Third mitosis → 8 nuclei.
• The 8 nuclei organize to form the mature embryo sac.

Summary:

• 1 meiotic division to produce 4 megaspores.
• 3 mitotic divisions by the functional megaspore to produce 8 nuclei.