A spongy white bilobed structures present at the narrrow tip of Castor seed is

Options

A. Strophiole
B. Caruncle
C. Raphe
D. Remains of chalaza

Answer

**Step-by-Step Solution:**

1. **Understanding the Structure of Castor Seed:**
- The Castor seed is characterized by its spiny regma, which eventually splits into three sections, each containing a single seed. The seed itself has an oblong shape, being narrow at one end and broader at the other.

2. **Identifying the Seed Surfaces:**
- The seed has two distinct surfaces: the ventral surface, which is flat, and the dorsal surface, which is convex. The ventral surface is where the seed is more likely to be attached to the fruit.

3. **Observing the Color and Texture:**
- The Castor seed is typically mottled and dark brown in color, with a smooth and shiny surface, which is important for its identification.

4. **Locating the Bilobed Structure:**
- At the narrow tip of the seed, there is a distinctive white spongy bilobed structure. This is a key feature to identify.

5. **Identifying the Structure:**
- This white spongy bilobed structure at the tip of the Castor seed is known as the **caruncle**. It serves a specific purpose in seed germination and development.

6. **Eliminating Other Options:**
- Other structures mentioned in the options, such as endosperm, cotyledons, tegmen, radical, chalaza, rafay, and strofoglio, do not fit the description of the bilobed structure at the tip of the seed. Thus, they can be ruled out.

7. **Final Answer:**
- The correct answer to the question is that the spongy white bilobed structure present at the narrow tip of the Castor seed is called the **caruncle**.

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