Who performed the experiments using canary grass to demonstrate the curvature of tip?

Options

A. E.Kurosawa
B. F.skoog
C. Went
D. Darwin

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the scientist who conducted experiments with canary grass to demonstrate the curvature of the tip, which is related to phototropism.

2. **Identifying the Phenomenon**: The bending of the plant towards the light source is known as phototropism. This occurs due to differential growth on the sides of the plant.

3. **Historical Context**: Charles Darwin and his son, Francis Darwin, were the first to observe this phenomenon in canary grass. They noted that the coleoptiles (the protective sheath covering the emerging shoot) of canary grass responded to light.

4. **Experimental Findings**: Through their experiments, they concluded that the tip of the coleoptile was responsible for this growth response. They identified that the hormone responsible for this curvature was auxin, which accumulates on the side of the plant that is away from the light, causing that side to grow more and thus bend towards the light.

5. **Conclusion**: Based on the historical experiments and findings, the correct answer to the question is Charles Darwin.

**Final Answer**: Charles Darwin performed the experiments using canary grass to demonstrate the curvature of the tip.

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