Assertion: Citrullus vulgaris is produced from a cross between 4n male and 2n female plants.
Reason: These triploid sterile plants do not bear seeds.

Options

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

Answer

To solve the assertion and reason question, we need to evaluate both statements and determine their validity.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that Citrullus vulgaris is produced from a cross between 4n male and 2n female plants.
- Here, "4n" refers to a tetraploid (four sets of chromosomes) and "2n" refers to a diploid (two sets of chromosomes).

2. **Evaluating the Assertion**:
- Citrullus vulgaris, commonly known as watermelon, is typically a diploid plant (2n).
- The assertion claims it is produced from a cross involving a tetraploid male (4n) and a diploid female (2n), which is not accurate for the production of Citrullus vulgaris.
- Therefore, the assertion is **false**.

3. **Understanding the Reason**:
- The reason states that these triploid sterile plants do not bear seeds.
- Triploid plants (3n) are indeed often sterile and do not produce seeds because they cannot undergo normal meiosis due to the odd number of chromosome sets.

4. **Evaluating the Reason**:
- The reason is **true** because triploid plants are typically seedless due to their inability to produce viable gametes.

5. **Conclusion**:
- Since the assertion is false and the reason is true, we conclude that the correct relationship is that the assertion is false, but the reason is true.

### Final Answer:
- The assertion is false, and the reason is true. Therefore, the correct option is that the assertion is false and the reason is true.

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