Which of the following organisms contain mantle, shell, and gills?

Options

A. Unio
B. Euglena
C. Octopus
D. Aurelia

Answer

To determine which organisms contain a mantle, shell, and gills, we can follow these steps:

### Step 1: Understand the Key Terms
- **Mantle**: A significant part of the anatomy in certain animals, particularly in mollusks, which secretes the shell.
- **Shell**: A hard protective outer layer found in some animals, also typically associated with mollusks.
- **Gills**: Organs used for breathing in aquatic animals, allowing them to extract oxygen from water.

### Step 2: Identify the Relevant Phylum
- The organisms that typically possess a mantle, shell, and gills belong to the **Phylum Mollusca**. This phylum includes a variety of animals such as snails, clams, and octopuses.

### Step 3: Examples of Organisms
- Common examples of organisms in Phylum Mollusca that have a mantle, shell, and gills include:
- **Clams**: They have a hard shell, a mantle that secretes the shell, and gills for respiration.
- **Snails**: They possess a shell (in many species), a mantle, and gills (in aquatic snails).
- **Oysters**: Similar to clams, they have a shell, mantle, and gills.

### Step 4: Conclusion
- Therefore, the organisms that contain a mantle, shell, and gills are primarily found in **Phylum Mollusca**.

### Final Answer
The organisms that contain a mantle, shell, and gills belong to the **Phylum Mollusca**.

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