Which of the following statements is true?

Options

A. Wings of birds and insects are homologous organs.
B. Human hands and bird's wings are analogous organs.
C. Human hands and bat's wings are analogous organs.
D. Flipper of penguin and dolphin are analogous organs.

Explanation

To determine which of the statements regarding homologous and analogous organs is true, we need to analyze each statement based on the definitions of these terms.

### Step-by-step Solution:

1. **Understand Homologous Organs**:
- Homologous organs are those that have a common evolutionary origin but have diverged in function. For example, the forelimbs of humans and the wings of birds are homologous because they share a common structural anatomy, even though they serve different functions (manipulation vs. flight).

**Hint**: Look for structures that share a common origin but serve different purposes.

2. **Understand Analogous Organs**:
- Analogous organs, on the other hand, do not share a common evolutionary origin but perform similar functions due to adaptation to similar environments. An example is the wings of birds and insects; both are used for flight but evolved independently.

**Hint**: Identify structures that perform the same function but do not share a common origin.

3. **Evaluate Each Statement**:
- **Statement 1**: "Wing of bird and insect is homologous organ."
- Incorrect. They are analogous because they serve the same function (flight) but have different origins.

- **Statement 2**: "Human hand and bird wings are analogous organs."
- Incorrect. They are homologous organs because they share a common origin (both are vertebrate limbs) but have different functions.

- **Statement 3**: "Human hand and bat wings are analogous."
- Incorrect. They are homologous organs as both are derived from a common mammalian ancestor, despite their different functions.

- **Statement 4**: "Flipper of penguin and dolphin are analogous organs."
- Correct. They are analogous because penguins (birds) and dolphins (mammals) have different evolutionary origins but both use their flippers for swimming.

4. **Conclusion**:
- The only true statement among the options provided is that the flipper of a penguin and a dolphin are analogous organs.

### Final Answer:
The correct statement is: "Flipper of penguin and dolphin are analogous organs."