What do you think is the correct sequence of the development of the embryo sac ?

Options

A. Archesporium `rarr` megaspore mother cell `rarr` megaspore `rarr` embryo sac
B. Archesporium `rarr` measpore `rarr` megaspore mother cell `rarr` embryo sac
C. Arcehsporium `rarr` megasporangium `rarr` embryo sac `rarr` embryo
D. Archesporium `rarr` nucellus `rarr` embryo sac `rarr` megaspore

Answer

To determine the correct sequence of the development of the embryo sac, we need to understand the stages involved in its formation. Here’s a step-by-step breakdown of the process:

### Step-by-Step Solution:

1. **Archesporium Formation**: The process begins with the formation of the archesporium, which is a group of cells in the ovule that will give rise to the megasporangium.

2. **Megasporangium Development**: The archesporium differentiates into the megasporangium, which is also known as the megasporangial tissue.

3. **Megaspore Mother Cell**: Within the megasporangium, one of the cells differentiates into the megaspore mother cell (also called the megasporocyte). This cell is diploid (2n) and will undergo meiosis.

4. **Meiosis and Megaspores Formation**: The megaspore mother cell undergoes meiosis to produce four haploid (n) megaspores. Typically, three of these megaspores degenerate, leaving one functional megaspore.

5. **Development of the Embryo Sac**: The surviving megaspore undergoes mitotic divisions to develop into the embryo sac, which is the female gametophyte. This structure will eventually contain the egg cell and synergids.

### Correct Sequence:
Based on the above steps, the correct sequence of development is:
1. Archesporium
2. Megasporangium (Megaspore Mother Cell)
3. Megaspore
4. Embryo Sac

Thus, the correct option is the first one: **Archesporium, Megaspore Mother Cell, Megaspore, Embryo Sac**.