Viral infection is usually absent in

Options

A. Phloem cells
B. Xylem cells
C. Pith cells
D. Apical meristem

Answer

To solve the question "Viral infection is usually absent in," we need to analyze the options provided: phloem cells, xylem cells, pit cells, and apical meristem.

### Step-by-Step Solution:

1. **Understanding Viral Infection in Plants**:
- Viruses typically spread through the vascular system of plants, which includes xylem and phloem. These tissues are responsible for the transport of nutrients and water, and they can serve as pathways for viral movement.

2. **Analyzing the Options**:
- **Phloem Cells**: These cells are part of the vascular system and are known to be susceptible to viral infections as they transport sugars and other organic compounds.
- **Xylem Cells**: Similar to phloem, xylem cells are also part of the vascular system, primarily involved in water transport. They can also be infected by viruses.
- **Pit Cells**: These are specialized cells found in certain types of tissues but are not specifically known to be resistant to viral infections.
- **Apical Meristem**: This is the region of actively dividing cells at the tips of roots and shoots. The cells here are pluripotent and have not yet differentiated into specific cell types, including vascular tissues.

3. **Identifying the Correct Answer**:
- The apical meristem is usually uninfected by viruses because it has not developed vascular tissues (xylem and phloem) through which viruses can spread. The rapid growth and undifferentiated nature of these cells contribute to their resistance to viral infections.

4. **Conclusion**:
- Based on the analysis, the correct answer to the question is **apical meristem**. Viral infections are usually absent in this region due to the lack of developed vascular tissues and the unique properties of the meristematic cells.

### Final Answer:
Viral infection is usually absent in **apical meristem**.