Bufo (toad) is different from Rana (frog) in having

Options

A. an exclusively aquatic life
B. poorly developed tympanum
C. smooth and slippery skin
D. paired parotoid glands situated behind tympanum

Answer

To differentiate Bufo (toad) from Rana (frog), we need to focus on the specific characteristics that are unique to toads. Here’s a step-by-step breakdown of the solution:

### Step-by-Step Solution:

1. **Identify the Organisms**: Recognize that Bufo refers to toads and Rana refers to frogs. Both belong to the phylum Amphibia.

2. **Understand Their Habitats**: Both toads and frogs can live in terrestrial (land) and aquatic (water) environments. Therefore, habitat is not a distinguishing feature.

3. **Examine the Tympanum**: The tympanum is an external ear structure. Both toads and frogs have tympanums, and they are not poorly developed in toads, making this option incorrect.

4. **Analyze Skin Texture**: Toads have dry, bumpy skin, while frogs have smooth and moist skin. The statement that toads have smooth and slippery skin is incorrect.

5. **Look for Unique Features**: The most distinguishing feature of toads is the presence of paired parotid glands located behind the tympanum. These glands secrete a milky toxin that serves as a defense mechanism against predators.

6. **Conclusion**: The correct answer is that Bufo (toad) is different from Rana (frog) in having paired parotid glands situated behind the tympanum.

### Final Answer:
Bufo (toad) is different from Rana (frog) in having paired parotid glands situated behind the tympanum.

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