Assertion (A) Secondary growth in dicot roots occur with the help of vascular cambium and phellogen.
Reason (R ) Vascular cambium is formed from conjuctive parenchyma and part of pericycle.

Options

A. If both Assertion and Reason are true and Reason is 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 and false.

Answer

To solve the assertion and reason question, we will analyze both the assertion (A) and the reason (R) statements step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that "Secondary growth in dicot roots occurs with the help of vascular cambium and phellogen."
- In dicot plants, secondary growth is characterized by an increase in girth, which is facilitated by the formation of secondary xylem (wood) and secondary phloem (bark). This process is indeed dependent on the vascular cambium (which produces xylem and phloem) and phellogen (cork cambium, which produces cork).

2. **Understanding the Reason (R)**:
- The reason states that "Vascular cambium is formed from conjunctive parenchyma and part of pericycle."
- The vascular cambium in dicot roots originates from the pericycle and the conjunctive parenchyma. This is a true statement as the cambium forms a ring that contributes to secondary growth.

3. **Evaluating the Truth of Both Statements**:
- Both the assertion and the reason are true statements. The assertion correctly describes the role of vascular cambium and phellogen in secondary growth, while the reason accurately explains the origin of the vascular cambium.

4. **Conclusion**:
- Since both the assertion and the reason are true, and the reason correctly explains the assertion, we conclude that the assertion is supported by the reason.

### Final Answer:
Both the assertion (A) and the reason (R) are true, and the reason supports the assertion.

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