AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
(C) Stimulation of the development of secondary sexual characters in males
This is a function of testosterone, not thyroxin. Thyroxin regulates metabolism, body temperature, heartbeat, and physical/mental development.
The question asks which option is NOT a function of thyroxin. The source passage (Chapter 7) clearly states that testosterone brings about changes in appearance (secondary sexual characters) in boys at puberty — not thyroxin. Thyroxin's functions include regulation of carbohydrate, protein, and fat metabolism, heart rate, body temperature, and childhood development. Examiners expect students to distinguish between hormones and their specific roles.