In frog, the vertebrae with an anterior convex surface is

Options

A. (a) Atlas
B. (b) Urostyle
C. (c) 8th vertebra
D. (d) 9th vertebra

Answer

To answer the question regarding which vertebra in a frog has an anterior convex surface, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of the Frog's Vertebral Column**:
- The vertebral column of a frog consists of a series of vertebrae that are numbered sequentially.

2. **Identify the Vertebrae**:
- The vertebral column of a frog typically comprises 10 vertebrae, starting from the atlas (the first vertebra) to the urostyle (the last vertebra).

3. **Locate the Anterior Convex Surface**:
- Among these vertebrae, we need to identify which one has an anterior convex surface.

4. **Examine Each Vertebra**:
- The first vertebra (atlas) is known for its unique structure but does not have a convex surface facing anteriorly.
- As we move through the vertebrae, we observe that the majority have a concave surface.

5. **Identify the Ninth Vertebra**:
- Upon examining the vertebrae, it is noted that the ninth vertebra is the one that has an anterior convex surface.

6. **Conclude the Answer**:
- Therefore, the vertebra in the frog that has an anterior convex surface is the ninth vertebra.

### Final Answer:
The vertebra with an anterior convex surface in a frog is the **ninth vertebra**.

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