Find out the incorrect statement w.r.t. frog-

Options

A. Only tympanum can be seen externally
B. Columnae carnaeae are present in ventricle
C. Bidder's canal communicates with the oviduct
D. Vasa efferentia are 10-12 in number

Answer

To find the incorrect statement with respect to frogs, we will analyze each of the provided options step by step.

### Step-by-Step Solution:

1. **Analyze the First Statement: "Only tympanum can be seen externally."**
- Frogs do not have external ears like humans. Instead, they have a tympanum, which is a membrane that functions similarly to an ear drum. This statement is correct.

2. **Analyze the Second Statement: "Columnae carnea are present in ventricles."**
- Columnae carnea, also known as muscular columns, are indeed present in the ventricles of a frog's heart. Frogs have a three-chambered heart consisting of two atria and one ventricle, where these structures are found. This statement is also correct.

3. **Analyze the Third Statement: "Bidus canal communicates with the oviduct."**
- The Bidus canal is part of the male reproductive system in frogs and does not communicate with the oviduct, which is part of the female reproductive system. This statement is incorrect.

4. **Conclusion:**
- The incorrect statement with respect to frogs is: "Bidus canal communicates with the oviduct."

### Final Answer:
The incorrect statement is: **"Bidus canal communicates with the oviduct."**

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