Which one of the following class of phylum mollusca is incorrectly matched with its general characteristics?

Options

A. Gastropoda- Larvae are bilaterally symmetrical, but in adult, the twisting of viscera makes them lose this symmetry. Some, like land snail and slug (a shell-less form), live on land.
B. Bivalvia- they are sedentary filter feeders.
C. Cephalopoda- They are at the apex of invertebrate evolution in terms of learned behavious they exhibit. The eyes are image forming, same what similar to ours.
D. Pelecypoda- They have sensory tentacles and their foot is reduced into a tongue-shaped structure which helps them to burrow into sea floor.

Explanation

To solve the question of which class of the phylum Mollusca is incorrectly matched with its general characteristics, we will analyze the characteristics of each class mentioned in the question.

### Step-by-Step Solution:

1. **Identify the Classes of Mollusca**:
- The main classes of the phylum Mollusca include Gastropoda, Bivalvia, Cephalopoda, and Polyplacophora.

2. **Analyze Gastropoda**:
- Gastropoda includes snails and slugs.
- Characteristics: Larvae are bilaterally symmetrical, but adults lose this symmetry due to torsion. Some are shell-less and terrestrial.
- Conclusion: The characteristics of Gastropoda are correctly matched.

3. **Analyze Bivalvia**:
- Bivalvia includes clams and oysters.
- Characteristics: They are sedentary filter feeders and have an unsegmented body.
- Conclusion: The characteristics of Bivalvia are correctly matched.

4. **Analyze Cephalopoda**:
- Cephalopoda includes octopuses and squids.
- Characteristics: They are at the apex of invertebrate evolution, exhibiting intelligence and image-forming capabilities.
- Conclusion: The characteristics of Cephalopoda are correctly matched.

5. **Analyze Polyplacophora (Pallisipoda)**:
- Polyplacophora includes chitons.
- Characteristics: They are commonly referred to as bivalves, but they do not have sensory tentacles, and their foot is well-developed, not reduced to a tongue-shaped structure.
- Conclusion: The characteristics of Polyplacophora are incorrectly matched, as they do not have sensory tentacles and their foot is not reduced.

6. **Final Conclusion**:
- The class that is incorrectly matched with its general characteristics is **Polyplacophora (Pallisipoda)**, as it is stated to have sensory tentacles and a reduced foot, which is incorrect.

### Answer:
The incorrectly matched class of phylum Mollusca is **Polyplacophora (Pallisipoda)**.

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