Which one of the following groups of animals is correctly matched with its characteristic feature without any exception ?

Options

A. a) Reptilla : possess 3-chambered heart with an incompletely divided ventricle
B. b) Chordata : possess a mouth with an upper and a lower jaw
C. c) Chondrichthyes : possess cartilaginous endoskeleton,
D. d) Mammalia : give birth to young ones.

Explanation

To determine which group of animals is correctly matched with its characteristic feature without any exceptions, we will analyze each option step by step:

### Step 1: Analyze Option A
- **Group**: Reptiles
- **Characteristic Feature**: Possess a three-chambered heart with incompletely divided ventricles.
- **Analysis**: While most reptiles do have a three-chambered heart, crocodiles are an exception as they possess a four-chambered heart.
- **Conclusion**: This option is not correctly matched.

### Step 2: Analyze Option B
- **Group**: Caudata (Amphibians)
- **Characteristic Feature**: Possess a mouth with an upper and a lower jaw.
- **Analysis**: The superclass Agnatha within the phylum Chordata consists of jawless fishes, which means not all members of Caudata have upper and lower jaws.
- **Conclusion**: This option is also not correctly matched.

### Step 3: Analyze Option C
- **Group**: Chondrichthyes (Cartilaginous fishes)
- **Characteristic Feature**: Possess a cartilaginous endoskeleton.
- **Analysis**: Chondrichthyes, which includes sharks and rays, indeed possess a cartilaginous endoskeleton, and there are no exceptions within this group.
- **Conclusion**: This option is correctly matched.

### Step 4: Analyze Option D
- **Group**: Mammalia
- **Characteristic Feature**: Give birth to young ones.
- **Analysis**: While most mammals give live birth, there are exceptions such as monotremes (e.g., platypus) and marsupials (e.g., kangaroos) that lay eggs or have a different reproductive method.
- **Conclusion**: This option is not correctly matched.

### Final Conclusion
The only group of animals that is correctly matched with its characteristic feature without any exceptions is **Option C: Chondrichthyes**, which possess a cartilaginous endoskeleton.

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