Mule, which is produced from the mating of male donkey and a mare ( female horse ), is an example of which type of reproductive isolation ?

Options

A. Hybrid breakdown
B. Hybrid sterility
C. Hybrid inviability
D. Reverse evolution

Answer

To answer the question regarding the reproductive isolation type exemplified by mules, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Definition of Mule**:
- A mule is a hybrid organism that results from the mating of a male donkey (Equus asinus) and a female horse (Equus ferus caballus).

2. **Identifying the Nature of the Hybrid**:
- Mules are hybrids, meaning they are produced from two different species. In this case, the male donkey and the female horse are two distinct species.

3. **Assessing the Fertility of Mules**:
- One key characteristic of mules is that they are typically sterile, meaning they cannot reproduce. This sterility arises due to the differing number of chromosomes in the parent species, which leads to complications during meiosis.

4. **Categorizing the Type of Reproductive Isolation**:
- The fact that mules cannot produce offspring indicates a specific type of reproductive isolation known as **hybrid sterility**. This occurs when the hybrid offspring (in this case, the mule) is unable to reproduce.

5. **Excluding Other Types of Reproductive Isolation**:
- Other types of reproductive isolation include:
- **Hybrid inviability**: where the hybrid does not survive to birth.
- **Hybrid breakdown**: where the first generation of hybrids is viable but subsequent generations are not.
- **Reverse evolution**: which is unrelated to reproductive isolation.
- Since mules are born and live but cannot reproduce, hybrid sterility is the correct classification.

### Final Answer:
The type of reproductive isolation exemplified by mules is **hybrid sterility**.

---