Cork cambium is

Options

A. Secondary exylem from secondary phloem
B. Primary xylem from primary phloem
C. Phellem from phelloderm
D. Phellogen from phelloderm

Answer

### Step-by-Step Solution:

1. **Understanding Cork Cambium**:
- Cork cambium is a type of lateral meristem found in plants. It is responsible for the production of cork cells, which are part of the protective outer layer of the plant.

2. **Identifying the Role of Cork Cambium**:
- The primary function of cork cambium is to produce cork cells (phellem) and phalloderm (phelloderm). Together, these tissues form the periderm, which replaces the epidermis in older stems and roots.

3. **Differentiating Between Terms**:
- Cork cambium (also known as phellogen) is distinct from primary and secondary xylem and phloem. It does not produce primary xylem or phloem but rather secondary tissues.
- Phalloderm is the inner layer of cells produced by cork cambium, while cork cells are the outer protective layer.

4. **Identifying the Correct Option**:
- The question presents four options regarding what cork cambium produces. The correct relationship is that cork cambium (phellogen) produces phalloderm from itself, making the fourth option correct: "phallogen from phalloderm."

5. **Conclusion**:
- Therefore, the answer to the question "Cork cambium is" is that it produces phallogen from phalloderm.