Delay of senescence of Richmond Lang effect is a physiological effect of

Options

A. IAA
B. CK
C. GA
D. `C_(2)H_(4)`

Answer

To solve the question regarding the physiological effect of the delay of senescence in the Richmond-Lange effect, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Richmond-Lange Effect**:
- The Richmond-Lange effect is a phenomenon observed in plants where the application of certain plant growth regulators can delay the aging process (senescence) of leaves and other plant parts.

2. **Identify the Key Plant Growth Regulators**:
- The options provided are:
- IAA (Indole Acetic Acid - a type of auxin)
- CK (Cytokinin)
- GA (Gibberellic Acid)
- C2H4 (Ethylene)

3. **Research the Role of Each Regulator**:
- **IAA (Indole Acetic Acid)**: Primarily involved in cell elongation and growth.
- **CK (Cytokinin)**: Known to promote cell division and delay senescence. It plays a crucial role in maintaining the vitality of plant tissues.
- **GA (Gibberellic Acid)**: Mainly involved in promoting growth and elongation of stems and seeds.
- **C2H4 (Ethylene)**: Generally associated with promoting senescence and ripening.

4. **Connect the Effect to the Correct Regulator**:
- Since the Richmond-Lange effect specifically refers to the delay of senescence, the key regulator responsible for this effect is cytokinin (CK). Cytokinins are known to inhibit the aging process in plants.

5. **Select the Correct Answer**:
- Based on the information gathered, the correct answer to the question is **CK (Cytokinin)**.

### Final Answer:
The delay of senescence of the Richmond-Lange effect is a physiological effect of **Cytokinin (CK)**.

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