Whales have no limbs bats have wings , yet both of them are included in Mammalia . The reason is , they have

Options

A. seven cervival vertebrae
B. 12 pairs of cranial nerves
C. mammary glands
D. all of these

Answer

To solve the question of why both whales and bats are included in the class Mammalia despite their differing characteristics, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Characteristics of Mammals**:
- Mammals are characterized by certain features that distinguish them from other animal classes. These include the presence of mammary glands, a specific number of cervical vertebrae, and cranial nerves.

2. **Examine the Features of Whales and Bats**:
- Whales, which are aquatic mammals, have adapted to life in water and lack traditional limbs.
- Bats, on the other hand, are the only mammals capable of sustained flight and have wings, which are modified forelimbs.

3. **Common Mammalian Traits**:
- Both whales and bats share key mammalian traits:
- **7 Cervical Vertebrae**: Regardless of their body structure, all mammals typically have seven cervical vertebrae.
- **12 Pairs of Cranial Nerves**: This is a common feature in mammals that facilitates various sensory and motor functions.
- **Mammary Glands**: Both whales and bats possess mammary glands, which are essential for nursing their young.

4. **Conclusion**:
- The reason both whales and bats are classified under Mammalia is that they share these fundamental mammalian characteristics, despite their adaptations to different environments (aquatic for whales and aerial for bats).

5. **Final Answer**:
- Therefore, the correct answer to the question is "all of this," as all the mentioned characteristics (7 cervical vertebrae, 12 pairs of cranial nerves, and mammary glands) are reasons for their classification in Mammalia.