An internal shell is absent in

Options

A. Sepia
B. Loligo
C. Pila
D. Both 1) and 2)

Answer

To determine which organism lacks an internal shell among the options given (sepia, loligo, pila, or both 1 and 2), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Shells**:
- A shell can be either external or internal. An internal shell provides protection to the internal organs of the organism.

2. **Identify the Organisms**:
- The organisms in question are sepia (cuttlefish), loligo (squid), and pila (a type of snail).

3. **Analyze Sepia and Loligo**:
- Both sepia (cuttlefish) and loligo (squid) belong to the class Cephalopoda.
- Cephalopods typically have an internal shell.
- Sepia has a structure known as cuttlebone, which serves as an internal shell, while loligo has a flexible rod known as a pen, which is also an internal structure.

4. **Analyze Pila**:
- Pila is a type of gastropod (snail) and has an external shell.
- It does not possess an internal shell.

5. **Conclusion**:
- Since sepia and loligo both have internal shells, and pila has an external shell with no internal shell, the correct answer is **pila**.

### Final Answer:
An internal shell is absent in **pila**.

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