All vertebrates are chordates, but all chordates are not vertebrates. Comment on this statement.

Explanation

### Step-by-Step Solution:

1. **Understanding the Terms**:
- **Chordates**: This is a phylum that includes animals with a notochord, a dorsal nerve cord, pharyngeal slits, and a post-anal tail at some stage of their development.
- **Vertebrates**: This is a subphylum of chordates that specifically includes animals with a backbone or vertebral column.

2. **All Vertebrates are Chordates**:
- All vertebrates possess the characteristics of chordates, particularly during their embryonic stage. They have a notochord, which is a flexible rod-like structure that provides support.
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