Chordates differ from non-chordates in having

Options

A. Notochord
B. Dorsal hollow nerve cord
C. Pharyngeal gill slits
D. All of the above

Answer

To answer the question "Chordates differ from non-chordates in having?", we will analyze the key characteristics that define chordates and how they differ from non-chordates.

### Step-by-Step Solution:

1. **Identify the Key Features of Chordates**:
- Chordates are characterized by the presence of certain structures during at least some stage of their life cycle. The primary features include:
- Notochord
- Dorsal hollow nerve cord
- Pharyngeal gill slits

2. **Analyze Each Option**:
- **Option A: Notochord**:
- The notochord is a flexible rod-like structure that provides support. It is present in all chordates at some stage of development and is absent in non-chordates. This option is correct.

- **Option B: Dorsal Hollow Nerve Cord**:
- Chordates possess a dorsal hollow nerve cord, which is located on the back side of the organism. In contrast, non-chordates typically have a ventral solid nerve cord. This option is also correct.

- **Option C: Pharyngeal Gill Slits**:
- Pharyngeal gill slits are openings in the pharynx that are present in chordates during some stage of development. Non-chordates do not have these structures. Thus, this option is correct as well.

3. **Conclusion**:
- Since all three options (A, B, and C) are correct and represent features that distinguish chordates from non-chordates, the correct answer is:
- **Option D: All of the above**.

### Final Answer:
The correct answer is D. All of the above.

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