Diplospory is direct (nonmeiotic) development of diploid embryo sac from

Options

A. Diploid megaspore mother cell
B. Diploid integument call
C. Diploid nucellar cell
D. All the above

Answer

### Step-by-Step Text Solution:

1. **Understanding Diplospory**: Diplospory is a reproductive process in plants where a diploid embryo sac develops directly from a diploid structure without undergoing meiosis. This means that the embryo sac is formed without the reduction of chromosome number typical of meiosis.

2. **Identifying the Source of the Embryo Sac**: In diplospory, the diploid embryo sac originates from a diploid megaspore mother cell. This cell is crucial as it is the starting point for the development of the embryo sac.

3. **Process of Development**: The diploid megaspore mother cell undergoes mitotic divisions instead of meiotic divisions. This results in the formation of a diploid embryo sac, which contains diploid cells, including egg cells, synergids, and antipodal cells.

4. **Analyzing the Options**:
- **Option 1**: Diploid megaspore mother cell - This is correct as it is the source of the diploid embryo sac.
- **Option 2**: Diploid integument cell - This is incorrect as integument cells do not directly give rise to the embryo sac.
- **Option 3**: Diploid nucellar cell - This is also incorrect as nucellar cells are not the direct source of the embryo sac in diplospory.
- **Option 4**: All of the above - This is incorrect since only the first option is valid.

5. **Conclusion**: The correct answer to the question is **Option 1: Diploid megaspore mother cell**. This is the structure from which the diploid embryo sac develops directly in the process of diplospory.