Metamorphosis of tadpole larva is controlled by ……………. .

Explanation

**Step-by-Step Solution:**

1. **Understanding Metamorphosis**: Metamorphosis refers to the biological process where an organism undergoes a significant change in its form and structure from an immature stage to an adult stage. In the case of tadpoles, this process involves transforming from a tadpole larva to an adult frog.

2. **Identifying the Process in Tadpoles**: The metamorphosis of tadpoles specifically involves changes such as the development of limbs, the absorption of the tail, and the transition from gills to lungs for breathing.

3. **Role of Hormones**: Hormones play a crucial role in regulating metamorphosis. In amphibians, the primary hormone responsible for this transformation is thyroxine.

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