Which one of the following correctly describes the homologous structures?

Options

A. Organs appearing only in embryonic stage arid disappearing later in the adult
B. Organs with anatomical similarities, but performing different functions
C. Organs with anatomical dissimilarities, but performing same functions
D. Organs that have no function now, but had an important function in ancestors

Explanation

To answer the question "Which one of the following correctly describes the homologous structures?", we can follow these steps:

### Step-by-Step Solution

1. **Understanding Homologous Structures**:
- Homologous structures are anatomical features in different species that share a common ancestry. They may have different functions but exhibit similar structural features.

2. **Identifying Characteristics**:
- Homologous structures are characterized by:
- Similar anatomical features (e.g., bone structure).
- Different functions (e.g., forelimbs of different animals used for flying, swimming, running, or grasping).

3. **Examples of Homologous Structures**:
- Common examples include the forelimbs of mammals such as bats (flying), whales (swimming), cheetahs (running), and humans (grasping). Despite their different functions, they share a similar bone structure (humerus, radius, ulna, etc.).

4. **Differentiating from Analogous Structures**:
- It is important to differentiate homologous structures from analogous structures, which have different anatomical features but perform similar functions (e.g., wings of birds and insects).

5. **Conclusion**:
- The correct description of homologous structures is: "organs with anatomical similarities but different functions."

### Final Answer
The correct description of homologous structures is: **"organs with anatomical similarities but different functions."**

---