Nuclear or cellular nature of endosperm can be known at a

Options

A. Mature stage
B. Cordate stage of embryo
C. First and subsequent divisions of PEN
D. beginning of divisions in embryo

Answer

To determine the nuclear or cellular nature of endosperm in flowering plants, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Endosperm**:
- Endosperm is a tissue that provides nutrition to the developing embryo in seed plants. It can exist in two forms: nuclear and cellular.

2. **Nuclear Endosperm**:
- Nuclear endosperm is the initial form of endosperm. It is characterized by the presence of a multinucleate structure, where multiple nuclei exist within a single cell without cell walls separating them.

3. **Cellular Endosperm**:
- Cellular endosperm is formed after the nuclear stage. It involves the division of the primary endosperm nucleus (PEN) into individual cells, leading to a cellular structure where each nucleus is enclosed within a cell wall.

4. **Identification Stages**:
- The nuclear nature of endosperm can be observed at the initial stages of development when the endosperm is still multinucleate.
- The transition to cellular endosperm is marked by the first cell division, which occurs shortly after fertilization.

5. **Mature Stage**:
- The mature stage of endosperm is typically cellular, where the endosperm is fully developed and provides nutrition to the embryo.

6. **Correct Option**:
- The nuclear or cellular nature of endosperm can be identified at the initial stages of development, particularly when observing the primary endosperm nucleus and its subsequent divisions.

### Conclusion:
The nuclear or cellular nature of endosperm can be known at the initial stage of development, particularly during the formation and division of the primary endosperm nucleus.