When only the first division is followed by cytokinesis, the development of endosperm is called

Options

A. cellular
B. nuclear
C. ruminate
D. helobial

Answer

To answer the question, "When only the first division is followed by cytokinesis, the development of endosperm is called," we need to analyze the types of endosperm development and identify the correct one based on the provided information.

### Step-by-Step Solution:

1. **Understanding Endosperm Development**:
- Endosperm is the tissue that provides nutrition to the developing embryo in seed plants. Its development can occur in different ways depending on the type of cytokinesis that follows the division of the primary endosperm nucleus.

2. **Types of Endosperm**:
- **Cellular Endosperm**: In this type, after the primary endosperm nucleus undergoes karyokinesis (nuclear division), cytokinesis (cell division) follows immediately, resulting in the formation of multiple cells. This is not the correct answer for our question.

- **Nuclear Endosperm**: Here, karyokinesis occurs without cytokinesis, leading to a multinucleated structure. This type is exemplified by coconut milk. This is also not the correct answer.

- **Ruminate Endosperm**: This type does not pertain to the question about cytokinesis following the first division. Therefore, it is not the correct option.

- **Halobial Endosperm**: This is the type we are looking for. In halobial endosperm, the first division of the primary endosperm nucleus is followed by a transverse cytokinesis, resulting in two unequal cells (a larger micropylar cell and a smaller chalazal cell). After this initial division, further development occurs similarly to the nuclear endosperm, without additional cytokinesis.

3. **Conclusion**:
- The correct answer to the question is **Halobial Endosperm**. This type of endosperm development occurs in some monocots and is characterized by the first division being followed by cytokinesis, leading to the formation of two unequal cells.

### Final Answer:
The development of endosperm when only the first division is followed by cytokinesis is called **Halobial Endosperm**.