Assertion: In Cucurbita stem, vascular bundles are conjoint, bicollateral, and their open or close.
Reason: The outer and inner cambium are present and only inner cambium is functional in Cucurbita stem.

Options

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

Answer

**Step-by-Step Solution:**

1. **Understanding the Assertion**: The assertion states that in the Cucurbita stem, the vascular bundles are described as conjoint, bicollateral, and can be either open or closed.
- **Conjoint** means that the xylem and phloem are located on the same radius of the vascular bundle.
- **Bicollateral** indicates that there are two phloem tissues (one on each side of the xylem), which is a characteristic of certain dicot plants.
- **Open or Closed** refers to the presence or absence of cambium between the xylem and phloem. Open vascular bundles have cambium, allowing for secondary growth, while closed ones do not.

2. **Analyzing the Reason**: The reason provided states that the outer and inner cambium are present, and only the inner cambium is functional in the Cucurbita stem.
- In Cucurbita, which belongs to the Cucurbitaceae family, the vascular bundles are indeed bicollateral and contain cambium.
- The assertion that only the inner cambium is functional is true, as it is responsible for secondary growth.

3. **Evaluating the Truth of Assertion and Reason**:
- The assertion is partially correct. While Cucurbita does have conjoint and bicollateral vascular bundles, they are specifically open vascular bundles, not both open and closed.
- The reason is correct in stating the presence of cambium, but it does not fully justify the assertion regarding the types of vascular bundles.

4. **Conclusion**: The assertion is incorrect because it suggests that both open and closed vascular bundles are present in Cucurbita, while only open bundles are found. The reason is accurate but does not support the assertion fully.

**Final Answer**: The assertion is false, and the reason is true. Therefore, the correct relationship is that the reason does not support the assertion.

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