Chordata includes

Options

A. Fishes, birds
B. Mammals, reptiles
C. Aves, reptilia
D. All of these

Answer

**Step-by-Step Solution:**

1. **Understanding Chordata**: The phylum Chordata includes animals that possess certain key characteristics at some stage of their life cycle. These characteristics include a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.

2. **Identifying the Groups**: Chordata is divided into several subphyla, the most notable of which include:
- **Vertebrates**: This group includes fish, amphibians, reptiles, birds, and mammals.
- **Invertebrate Chordates**: This group includes tunicates and lancelets, but they are less commonly discussed in the context of the question.

3. **Evaluating the Options**: The question provides several options:
- Option 1: Fish and birds
- Option 2: Mammals and reptiles
- Option 3: Eaves or reptilia (which seems to be a typographical error for "reptiles")
- Option 4: All of these

4. **Analyzing Each Option**:
- **Option 1**: Fish and birds are both part of Chordata.
- **Option 2**: Mammals and reptiles are also part of Chordata.
- **Option 3**: Reptilia (reptiles) is a class within Chordata.
- **Option 4**: This option states "all of these," which includes all the mentioned groups.

5. **Conclusion**: Since all the mentioned groups (fish, birds, mammals, reptiles) are part of the phylum Chordata, the correct answer is **Option 4: All of these**.

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