All tissues exterior to vascular cambium is called bark which indudes

Options

A. Phellogen + secondary xylem
B. Periderm + secondary xylem
C. Periderm + secondary phloem
D. Cork cambium + primary xylem

Answer

To answer the question regarding what all tissues exterior to the vascular cambium are called, and what they include, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Bark**:
- The term "bark" refers to all the tissues that are located outside the vascular cambium in a plant. This includes various layers that serve different functions.

**Hint**: Remember that bark is a collective term for tissues outside the vascular cambium.

2. **Identifying Components of Bark**:
- Bark is primarily composed of two main components: the periderm and the secondary phloem.
- The periderm itself consists of three layers:
- **Phelum**: The outermost layer, made up of cork cells that provide protection.
- **Pheloderm**: The inner layer of the periderm, which consists of living parenchyma cells.
- **Phelogen**: The cork cambium, which is responsible for producing the phelum and pheloderm.

**Hint**: Think of the periderm as a protective layer that includes cork and living cells.

3. **Defining Periderm**:
- The periderm is a key component of the bark and is formed during secondary growth. It replaces the epidermis in older stems and roots.

**Hint**: The periderm is essential for the protection and insulation of the plant.

4. **Including Secondary Phloem**:
- In addition to the periderm, the bark also includes secondary phloem, which is responsible for the transport of nutrients.

**Hint**: Secondary phloem is vital for the plant's nutrient transport system.

5. **Summarizing the Components of Bark**:
- Therefore, the bark includes:
- Periderm (which consists of phelum, pheloderm, and phelogen)
- Secondary phloem

**Hint**: Remember that bark is not just one layer but a combination of protective and transport tissues.

6. **Conclusion**:
- The correct answer to the question is that the bark includes both the periderm and the secondary phloem.

**Hint**: Look for options that mention both periderm and secondary phloem to find the correct answer.

### Final Answer:
The bark includes the periderm (which consists of phelum, pheloderm, and phelogen) and the secondary phloem.