Which one produces embryo sac

Options

A. Megaspore mother cell
B. Megaspore
C. Microspore
D. Embryo cell.

Answer

**Step-by-Step Solution:**

1. **Identify the Structure Involved**: The question asks about the production of the embryo sac. The embryo sac is formed from a specific type of spore in flowering plants.

2. **Understand the Role of Megaspore Mother Cell**: The diploid megaspore mother cell (also known as the megasporangium) is located within the ovule (nucellus) of the plant.

3. **Meiotic Division**: The megaspore mother cell undergoes meiosis, which is a type of cell division that reduces the chromosome number by half. This process results in the formation of four haploid megaspores.

4. **Selection of Functional Megaspore**: Out of the four haploid megaspores produced, three degenerate, leaving only one functional megaspore.

5. **Mitosis of the Functional Megaspore**: The functional megaspore undergoes three rounds of mitotic division without cytokinesis (the division of the cytoplasm), leading to the formation of eight nuclei.

6. **Organization of Nuclei**: These eight nuclei are then organized into a structure known as the embryo sac. This structure consists of seven cells: one egg cell, two synergids, one large central cell, and three antipodal cells.

7. **Conclusion**: Therefore, the correct answer to the question "Which one produces embryo sac?" is the **megaspores**, specifically the functional megaspore that develops into the embryo sac.

**Final Answer**: The correct option is **Megaspore**.

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