Cytokinins

Options

A. promote abscission
B. influence water movement
C. help retain chlorophyll
D. inhibit protoplasmic streaming

Explanation

**Step-by-Step Solution:**

1. **Understanding Cytokinins:**
- Cytokinins are a class of plant hormones that play a crucial role in promoting cell division and growth in plants. The term "kinin" indicates "division," which highlights their primary function.

2. **Production and Distribution:**
- Cytokinins are primarily produced in the roots of plants. Once synthesized, they are distributed throughout the plant via the xylem, which is responsible for transporting water and nutrients.

3. **Functions of Cytokinins:**
- The main functions of cytokinins include:
- Promoting cell division in roots and shoots.
- Influencing the growth of new leaves and shoots.
- Retaining chlorophyll in leaves, which is essential for photosynthesis.

4. **Analyzing the Options:**
- The question presents several options regarding the functions of cytokinins:
- **Promote Abscission:** This is incorrect as abscission refers to the shedding of leaves or fruits, which is not promoted by cytokinins.
- **Influence Water Movement:** Cytokinins do not directly affect water movement through the xylem.
- **Help in Retaining Chlorophyll:** This is correct. Cytokinins play a significant role in maintaining chlorophyll levels in leaves, aiding in photosynthesis.
- **Inhibit Protoplasmic Streaming:** This is also incorrect as cytokinins do not inhibit protoplasmic streaming.

5. **Conclusion:**
- Based on the analysis, the correct function of cytokinins is that they help in retaining chlorophyll in the leaves, which is vital for the plant's growth and photosynthesis.