Megaspores are produced from megaspore mother cells after

Options

A. meiotic division
B. mitotic division
C. formation fo thick wall
D. differntitation

Answer

**Step-by-Step Solution:**

1. **Understanding Megaspores and Megaspore Mother Cells**:
- Megaspores are produced from megaspore mother cells (also known as megasporangium).
- These cells are diploid (2n) and are located in the ovule of flowering plants.

2. **Type of Cell Division**:
- The megaspores are produced after meiotic division of the megaspore mother cells.
- Meiosis is a type of cell division that reduces the chromosome number by half, resulting in haploid (n) cells.

3. **Meiotic Division Process**:
- During meiosis, the diploid megaspore mother cell divides to form four haploid megaspores.
- This process involves two rounds of division: meiosis I and meiosis II.

4. **Outcome of Meiosis**:
- Out of the four haploid megaspores produced, three typically degenerate.
- One functional megaspore survives and develops into the female gametophyte.

5. **Formation of Female Gametophyte**:
- The surviving megaspore undergoes successive mitotic divisions.
- These divisions lead to the formation of an eight-celled structure known as the embryo sac, which is the female gametophyte.

6. **Structure of the Embryo Sac**:
- The embryo sac consists of eight nuclei arranged in a specific pattern: three at the micropilar end and two at the chalazal end, along with three antipodal cells.

**Final Answer**: Megaspores are produced from megaspore mother cells after meiotic division.

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