Assertion : Parthenogenesis does not play any role in organic evolution.
Reason : In parthenogenesis females develop into new organisms without fertilisation.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

### Step-by-Step Text Solution:

1. **Understanding Parthenogenesis**:
- Parthenogenesis is a form of asexual reproduction where an ovum develops into a new individual without fertilization by a male gamete. This means that only the female gamete (ovum) is involved in the process.

2. **Role of Variation in Evolution**:
- Evolution relies on genetic variation, which is primarily introduced through sexual reproduction. In sexual reproduction, the combination of genetic material from two parents leads to offspring with varied traits. This variation is crucial for natural selection and evolution.

3. **Impact of Parthenogenesis on Evolution**:
- Since parthenogenesis involves the development of offspring from a single gamete (the ovum), it does not introduce genetic variation. As a result, all offspring are genetically identical to the mother, which limits the potential for evolutionary change.

4. **Evaluating the Assertion**:
- The assertion states that "Parthenogenesis does not play any role in organic evolution." This is correct because the lack of genetic variation means that parthenogenetic organisms are less likely to adapt to changing environments, thus limiting their evolutionary potential.

5. **Evaluating the Reason**:
- The reason states that "In parthenogenesis, females develop into new organisms without fertilization." This statement is also correct, as it accurately describes the process of parthenogenesis.

6. **Relationship Between Assertion and Reason**:
- While both the assertion and the reason are true, the reason does not explain why parthenogenesis does not contribute to organic evolution. The assertion is about the impact on evolution, while the reason describes the mechanism of reproduction.

7. **Conclusion**:
- Therefore, the correct answer is that both the assertion and reason are true, but the reason is not the correct explanation for the assertion. The answer choice is B.