Collenchyma is absent in
(a) Monocot root
(b) Dicot root
(c) Monocot stem
(d) All of the above

Options

A. Root
B. Dicot stem
C. Monocots
D. Both 1 or 3

Answer

To determine where collenchyma is absent, let's analyze each option step by step:

1. **Understanding Collenchyma**:
- Collenchyma is a type of plant tissue characterized by its living cells that have irregularly thickened cell walls. These thickenings are primarily due to the deposition of cellulose, pectin, and hemicellulose.
- Collenchyma provides mechanical support to the plant, especially in areas that require flexibility.

2. **Analyzing the Options**:
- **(a) Monocot root**:
- Collenchyma is generally absent in the roots of monocots. Roots primarily consist of other types of tissues such as parenchyma and sclerenchyma for support and storage.
- **(b) Dicot root**:
- Similarly, collenchyma is also absent in dicot roots. The root structure in dicots does not include collenchyma, as it is not a fundamental tissue found in roots.
- **(c) Monocot stem**:
- In monocot stems, collenchyma is not typically present. Monocot stems are usually supported by sclerenchyma and other tissues.
- **(d) All of the above**:
- Since collenchyma is absent in monocot roots, dicot roots, and monocot stems, this option is correct.

3. **Conclusion**:
- Based on the analysis, collenchyma is absent in all the mentioned plant parts (monocot root, dicot root, and monocot stem). Therefore, the correct answer is **(d) All of the above**.