Chordates process

Options

A. Dorsal nerve cord placed below gut
B. Single hollow nerve cord placed dorsal to gut
C. Double ventral nerve cord
D. Single solid and ventral nerve cord

Answer

### Step-by-Step Solution:

1. **Understanding Chordates**: Chordates are a group of animals that share certain key characteristics during some stage of their development. These include the presence of a notochord, a dorsal nerve cord, pharyngeal gill slits, an endostyle, and a post-anal tail.

2. **Identifying the Nerve Cord**: Among the characteristics of chordates, the nerve cord is a crucial feature. It is important to note the position and structure of this nerve cord.

3. **Analyzing the Options**:
- **Option A**: "Dorsal nerve cord placed below gut" - This is incorrect because the dorsal nerve cord is not below the gut.
- **Option B**: "Single hollow nerve cord placed dorsal to gut" - This is correct as chordates possess a single hollow nerve cord that is located above (dorsal to) the gut.
- **Option C**: "Double ventral nerve cord" - This is incorrect as chordates do not have a double ventral nerve cord.
- **Option D**: "Single solid and ventral nerve cord" - This is also incorrect because the nerve cord is not solid and is not located ventrally.

4. **Conclusion**: Based on the analysis of the options, the correct answer is **Option B: Single hollow nerve cord placed dorsal to gut**.