One of the following can't be taken as the character of non-chordates

Options

A. Absence of notochord
B. heart is ventral
C. Gill slits are absent
D. Chitinous exoskeleton present

Explanation

To solve the question "One of the following can't be taken as the character of non-chordates," we need to analyze each option provided and determine which one does not apply to non-chordates.

### Step-by-Step Solution:

1. **Understanding Non-Chordates**:
- Non-chordates are a diverse group of animals that do not possess a notochord, which is a defining characteristic of chordates.

2. **Analyzing the Options**:
- **Option A: Absence of notochord**:
- This is a true statement for non-chordates, as they do not have a notochord. Therefore, this cannot be the correct answer.
- **Option B: Heart is ventral**:
- In non-chordates, the heart is typically dorsal (located on the back). Therefore, stating that the heart is ventral is incorrect for non-chordates, making this a potential answer.
- **Option C: Gill slits are absent**:
- Gill slits are indeed absent in non-chordates, as they are a characteristic feature of chordates. Thus, this statement is true for non-chordates.
- **Option D: Chitinous exoskeleton present**:
- A chitinous exoskeleton is found in many non-chordates, especially in arthropods. Therefore, this statement is also true for non-chordates.

3. **Identifying the Correct Answer**:
- From the analysis, the only statement that cannot be taken as a character of non-chordates is **Option B: Heart is ventral**. This is because, in non-chordates, the heart is typically dorsal.

### Final Answer:
The correct answer is **Option B: Heart is ventral**.

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