Fundamental tissue system of primary stem and root consists of

Options

A. Stele, Cortex
B. Cortex, Pith only
C. Cortex, Mesophyll, Pericycle, and Pith
D. Cortex, Pericycle, Pith, Medullary rays / conjuctive tissue

Answer

To answer the question regarding the fundamental tissue system of the primary stem and root, we need to understand the components and organization of the primary xylem in both structures.

### Step-by-Step Solution:

1. **Understanding Fundamental Tissue System**:
The fundamental tissue system in plants consists of three main types of tissues: parenchyma, collenchyma, and sclerenchyma. These tissues provide support, storage, and photosynthesis.

2. **Identifying Primary Xylem**:
The primary xylem is part of the vascular tissue system and is responsible for the conduction of water and minerals. It is divided into two types: protoxylem and metaxylem.

3. **Arrangement of Xylem in Stem and Root**:
- In stems, the arrangement of primary xylem is typically **endarch**, where protoxylem is located towards the center and metaxylem towards the periphery.
- In roots, the arrangement is usually **exarch**, where protoxylem is located towards the periphery and metaxylem is towards the center.

4. **Understanding Mesarch Condition**:
The mesarch condition occurs when protoxylem is surrounded by metaxylem. This arrangement can be found in certain plants and is a unique configuration of xylem.

5. **Conclusion**:
Therefore, the fundamental tissue system of the primary stem and root consists of parenchyma, collenchyma, and sclerenchyma, along with the vascular tissues (xylem and phloem). Specifically, for the xylem arrangement, the correct answer is that protoxylem is surrounded by metaxylem, which is referred to as the mesarch condition.

### Final Answer:
The fundamental tissue system of the primary stem and root consists of parenchyma, collenchyma, sclerenchyma, and vascular tissues, with the xylem arrangement being mesarch (protoxylem surrounded by metaxylem).

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