Eye lids are absent in

Options

A. Fish
B. Bird
C. Frog
D. Mammal

Answer

### Step-by-Step Solution:

1. **Identify the Question**: The question asks which group of animals lacks eyelids.

2. **Analyze the Options**: The options provided are fish, birds, frogs, and mammals. We need to evaluate each option to determine which one does not have eyelids.

3. **Examine Fish**:
- Fish belong to the subphylum Vertebrata and the phylum Chordata.
- In general, fish do not have eyelids. Instead, they have a protective transparent layer called the nictitating membrane or adipose eyelid, which is not a true eyelid.

4. **Examine Birds**:
- Birds also belong to the subphylum Vertebrata and the phylum Chordata.
- Birds have well-developed eyelids that help protect their eyes.

5. **Examine Frogs**:
- Frogs are amphibians and also belong to the subphylum Vertebrata and phylum Chordata.
- Frogs possess eyelids, including a nictitating membrane that helps with vision in water.

6. **Examine Mammals**:
- Mammals are another group within the subphylum Vertebrata and phylum Chordata.
- Mammals have fully developed eyelids that cover their eyes.

7. **Conclusion**: Based on the analysis, the only group that typically lacks true eyelids is fish. Therefore, the correct answer to the question is **fish**.

### Final Answer:
Eyelids are absent in **fish**.

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