Secondary growth usually does not occur in

Options

A. stems and roots of dicots
B. stems and roots of gymnosperms
C. stems and roots of monocots
D. both b and c

Explanation

**Step-by-Step Solution:**

1. **Understanding Secondary Growth:**
- Secondary growth refers to the increase in the girth or diameter of a plant. This type of growth is primarily facilitated by the lateral or secondary cambium.

2. **Identifying Where Secondary Growth Occurs:**
- Secondary growth typically occurs in dicots and gymnosperms, where the lateral cambium is present. This allows for the formation of secondary tissues, which contribute to the thickening of stems and roots.

3. **Analyzing Monocots:**
- In monocots, the lateral cambium is generally absent. Therefore, secondary growth does not occur in the stems and roots of monocots.

4. **Examining Roots of Both Monocots and Dicots:**
- In the roots of both monocots and dicots, the lateral cambium is also absent in monocots. While there may be some exceptions in dicots where certain tissues can form secondary cambium, this does not apply to monocots.

5. **Conclusion:**
- Based on the analysis, secondary growth usually does not occur in the stems and roots of monocots. Thus, the correct answer to the question is that secondary growth does not occur in the stems and roots of monocots.

**Final Answer:**
Secondary growth usually does not occur in the stems and roots of monocots.

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