Which of the following amino acids is a precursor for thyroid hormones?

Tyrosine is the correct answer because it plays a crucial role in the synthesis of thyroid hormones, specifically thyroxine (T4) and triiodothyronine (T3). In the body, tyrosine is converted from another amino acid called phenylalanine through a series of enzymatic reactions. Once formed, tyrosine is iodinated, and further modifications lead to the production of thyroid hormones.

Thyroid hormones are essential for regulating metabolism, growth, and development, demonstrating the important biochemical pathway starting from tyrosine. This metabolic connection emphasizes the significance of tyrosine as a precursor for these critical hormones in the body.