Assertion: The biological concept of species is based on reproductive isolation.
Reason: Tigon is the interspecific sterile hybrid produced in captive condition

Answer

**Step-by-Step Solution:**

1. **Understanding the Assertion:**
- The assertion states that "The biological concept of species is based on reproductive isolation." This means that different species are unable to interbreed due to various barriers that prevent reproduction.

2. **Explaining Reproductive Isolation:**
- Reproductive isolation can occur through various mechanisms such as temporal isolation (different mating seasons), behavioral isolation (different mating behaviors), and mechanical isolation (incompatible reproductive structures).

3. **Example of Reproductive Isolation:**
- An example provided is the lion (Panthera leo) and the tiger (Panthera tigris). Although they belong to the same genus (Panthera), they are different species and cannot reproduce with each other in the wild due to reproductive isolation.

4. **Understanding the Reason:**
- The reason states that "Tigon is the interspecific sterile hybrid produced in captive conditions." A tigon is a hybrid offspring of a male tiger and a female lion, produced under captive conditions.

5. **Explaining the Sterility of Hybrids:**
- While hybridization can occur in captivity, the resulting hybrids (like tigons) are often sterile. This means they cannot produce offspring of their own, which is a common characteristic of many hybrids due to differences in chromosome numbers or genetic incompatibility.

6. **Conclusion:**
- Both the assertion and the reason are true. The assertion correctly describes the concept of species and reproductive isolation, while the reason provides a specific example of a hybrid (tigon) that illustrates the consequences of reproductive isolation.

7. **Final Statement:**
- Therefore, both the assertion and the reason are true, and the reason is a correct explanation of the assertion.

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