Which of the following structures is homologus to the wing of a bird?

Options

A. Wing of a Moth
B. Hind limb of Rabbit
C. Flipper of Whale
D. Dorsal fin of a Shark

Answer

To determine which structure is homologous to the wing of a bird, we need to understand the concept of homology in biology. Homologous structures are those that share a common evolutionary origin but may serve different functions in different species.

### Step-by-Step Solution:

1. **Understanding Homologous Structures**:
- Homologous structures arise from a common ancestor and have similar anatomical features, even if they serve different functions. For example, the forelimbs of mammals, birds, and reptiles have similar bone structures but perform different tasks (e.g., flying, swimming, walking).

2. **Analyzing the Options**:
- **Option A: Wings of a Moth**:
- Moths are insects and have a different evolutionary origin compared to birds. Therefore, their wings are not homologous to bird wings.
- **Option B: Hind Limb of a Rabbit**:
- Rabbits are mammals, and while they share a common ancestor with birds, their limbs are adapted for different functions (walking vs. flying). They are not homologous to bird wings.
- **Option C: Flippers of a Whale**:
- Whales are mammals and share a common ancestor with birds. The flippers of a whale and the wings of a bird have different functions (swimming vs. flying) but share similar bone structures, making them homologous.
- **Option D: Dorsal Fins of a Shark**:
- Sharks are fish and have a completely different evolutionary lineage from birds. Their dorsal fins do not share a common origin with bird wings, so they are not homologous.

3. **Conclusion**:
- The only structure that is homologous to the wing of a bird is the **flippers of a whale** (Option C), as they share a common evolutionary origin and have similar anatomical structures.

### Final Answer:
**C. Flippers of a Whale**