Name the hormone which influence the tip of coleoptile and bend it towards light

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the name of the hormone that influences the tip of the coleoptile and causes it to bend towards light.

2. **Historical Context**: In 1881, Charles Darwin and his son Francis Darwin conducted experiments on the coleoptile of canary grass. They observed that the coleoptile bends towards a unilateral light source.

3. **Experiment Observation**: When the coleoptile is exposed to light from one direction, it bends towards the light. This bending is a response to the light stimulus.

4. **Role of the Coleoptile Tip**: The tip of the coleoptile is responsible for sensing light. The Darwins proposed that a substance (hormone) is produced at the tip and is responsible for the bending movement.

5. **Identification of the Hormone**: The substance that was identified as responsible for this bending is called auxin. Auxin is a plant hormone that regulates growth and is involved in the bending response of plants towards light.

6. **Conclusion**: Therefore, the hormone that influences the tip of the coleoptile and causes it to bend towards light is auxin.

**Final Answer**: The hormone is auxin.

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