Thyroxine is derived from tyrosine.

Explanation

**Step-by-Step Solution:**

1. **Understanding Thyroxine and Tyrosine:**
- Thyroxine (T4) is a hormone produced by the thyroid gland, which is an endocrine gland responsible for regulating metabolism, growth, and development.
- Tyrosine is an amino acid that serves as a building block for proteins and is also a precursor for the synthesis of several important hormones, including thyroxine.

2. **Production of Thyroxine:**
- The thyroid gland synthesizes thyroxine from the amino acid tyrosine. This process involves the addition of iodine to tyrosine, which is essential for the formation of the active thyroid hormones T3 (triiodothyronine) and T4 (thyroxine).
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