Cytokinin

Options

A. Is a hormone whose main function is the induction of cell divison
B. Is the process of cell division
C. Refers to cell movements
D. Causes dormancy.

Answer

### Step-by-Step Solution:

1. **Definition of Cytokinin**:
- Cytokinin is identified as a plant hormone.

2. **Primary Function**:
- The main role of cytokinin is to promote cell division in plants. This is a crucial function as it helps in the growth and development of plant tissues.

3. **Additional Function**:
- Cytokinins also play a role in delaying leaf senescence, which is the aging process of leaves. This means that they help in maintaining the vitality of leaves for a longer period.

4. **Understanding Leaf Senescence**:
- Leaf senescence refers to the aging process of leaves, which is often associated with the breakdown of chlorophyll, leading to yellowing and eventual leaf drop.

5. **Evaluation of Options**:
- Option 1 states that cytokinin is a hormone whose function is the induction of cell division. This is correct.
- Option 2 suggests that cytokinin is the process of cell division, which is incorrect as cytokinin is a hormone, not a process.
- Option 3 refers to cell movements, which is also incorrect as cytokinin does not primarily deal with movements.
- Option 4 states that cytokinin causes dormancy, which is incorrect; dormancy is associated with other hormones like gibberellins.

6. **Conclusion**:
- Based on the analysis, the correct answer is option number 1: Cytokinin is a hormone whose main function is the induction of cell division.