Cytokinin are said to be antiageing hormone because they delay the senescence by

Options

A. Controlling mobilisation of resources
B. Controlling protein synthesis
C. Decreased morphogenisis and high respiration
D. Both 1 & 2

Answer

**Step-by-Step Solution:**

1. **Understanding Cytokinins**: Cytokinins are plant hormones that play a crucial role in promoting cell division and growth. They are often referred to as anti-aging hormones because they help delay the aging process in plants.

2. **Mechanism of Action**: Cytokinins delay senescence (aging) in plants through two primary mechanisms:
- **Mobilization of Nutrients**: Cytokinins facilitate the movement of nutrients (both micro and macronutrients) to specific sites in the plant. This ensures that the cells have the necessary resources for growth and maintenance, which helps in delaying aging.
- **Regulation of Protein Synthesis**: Cytokinins also influence protein synthesis, which is vital for maintaining cellular functions and preventing the aging process. By controlling the synthesis of proteins, cytokinins help in sustaining the vitality of plant cells.

3. **Evaluating the Options**:
- **Option 1: Controlling mobilization of resources** - This is correct as cytokinins do mobilize nutrients.
- **Option 2: Controlling protein synthesis** - This is also correct since cytokinins regulate protein synthesis.
- **Option 3: Decreased morphogenesis and high respiration** - This is incorrect. Cytokinins promote morphogenesis (the development of structure) and do not increase respiration in a way that would contribute to aging.
- **Option 4: 1st and 2nd** - Since both the first and second options are correct, this option is the right choice.

4. **Conclusion**: Cytokinins are indeed anti-aging hormones because they delay senescence by controlling the mobilization of resources and regulating protein synthesis.

**Final Answer**: Cytokinins delay senescence by controlling mobilization of resources and controlling protein synthesis (Option 4: 1st and 2nd).

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