Corona radiata is derived from

Options

A. Membrana granulosa
B. Cumulus ovaricus
C. Theca interna
D. Theca externa.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the origin of the "corona radiata," which is a structure associated with the ovum (egg) in the female reproductive system.

2. **Identifying the Options**: The options provided are:
- A. Membrane granulosa
- B. Cumulus ovaricus
- C. Theca interna
- D. Theca externa

3. **Analyzing Each Option**:
- **A. Membrane granulosa**: This refers to the layer of granulosa cells that surround the primary oocyte and form the structure of the ovarian follicles. While it is involved in the development of the follicle, it does not directly give rise to the corona radiata.
- **B. Cumulus ovaricus**: This is a cluster of cells that surround the oocyte within the Graafian follicle. The innermost cells of this cluster are specifically known to form the corona radiata, making this option a strong candidate.
- **C. Theca interna**: This is the inner layer of the theca follicle, which provides support and nourishment but does not directly form the corona radiata.
- **D. Theca externa**: This is the outer layer of the theca follicle, which also does not contribute to the formation of the corona radiata.

4. **Conclusion**: Based on the analysis, the corona radiata is derived from the cumulus ovaricus, as it is the cluster of cells that directly surrounds the oocyte and contributes to the formation of the corona radiata.

5. **Final Answer**: Therefore, the correct answer is **B. Cumulus ovaricus**.

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