The collective used for phelloderm cork cambium and cork is

Options

A. pericycle
B. periderm
C. protoderm
D. procambium

Answer

To solve the question regarding the collective term used for phelloderm, cork cambium, and cork, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Terms**:
- **Phelloderm**: This is the inner layer of the periderm, which is formed by the cork cambium.
- **Cork Cambium**: Also known as phellogen, this is a layer of meristematic tissue that produces cork cells (phellem) towards the outside and phelloderm towards the inside.
- **Cork**: Also referred to as phellem, this is the outer protective layer that is produced by the cork cambium.

2. **Identifying the Collective Term**:
- The three components (phelloderm, cork cambium, and cork) are all part of the protective tissue system in plants.
- These layers collectively form a protective barrier for the plant, which is crucial for preventing water loss and protecting against pathogens.

3. **Recognizing the Correct Collective Term**:
- The collective term for phelloderm, cork cambium, and cork is **periderm**.
- Periderm is the term used to describe the outer protective layer of the plant that replaces the epidermis in stems and roots as they mature.

4. **Conclusion**:
- Therefore, the answer to the question is that the collective term for phelloderm, cork cambium, and cork is **periderm**.

### Final Answer:
The collective term for phelloderm, cork cambium, and cork is **periderm**.

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