In frogs, testes are attached to kidneys by a double fold of peritoneum known as :

Options

A. Pericardium
B. Mesorchium
C. Urinogenital duct
D. Vasa efferentia

Answer

To answer the question regarding the structure that connects the testes to the kidneys in frogs, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the name of the structure that connects the testes to the kidneys in frogs through a double fold of peritoneum.

2. **Analyzing the Options**: The options provided are:
- Pericardium
- Mesorchium
- Urinogenital duct
- Vasa efferentia

3. **Evaluating Each Option**:
- **Pericardium**: This is the outer layer surrounding the heart. It is not related to the kidneys or testes, so this option can be eliminated.
- **Mesorchium**: This is a double fold of peritoneum that attaches the testes to the kidneys. This option seems relevant to the question.
- **Urinogenital duct**: This duct is involved in the transport of both urine and sperm but does not specifically refer to the attachment of testes to kidneys. Therefore, this option can be eliminated.
- **Vasa efferentia**: These are ducts that carry sperm from the testes to the kidneys but do not describe the attachment structure. Thus, this option can also be eliminated.

4. **Conclusion**: After evaluating all the options, the correct answer is **Mesorchium**, as it is the structure that connects the testes to the kidneys in frogs.

### Final Answer:
In frogs, testes are attached to kidneys by a double fold of peritoneum known as **mesorchium**.

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