Consider the following statements: 1. Iodine is necessary for the thyroid gland to make adrenaline. 2. Iodine deficiency leads to goiter in human beings. 3. Iodine is secreted by pancreas and helps in regulating cholesterol level. Which of the statements given above is/are correct ?

Statement 1 is incorrect because iodine is essential for the synthesis of thyroxin (thyroid hormone), not adrenaline [c1, t6]. Adrenaline is produced by the adrenal medulla, located in the adrenal glands atop the kidneys [c4, t2, t3]. Statement 2 is correct; iodine deficiency impairs thyroid hormone production, leading to the enlargement of the thyroid gland, a condition known as goiter [c1, t1, t4]. Statement 3 is incorrect because iodine is not secreted by the pancreas; the pancreas primarily produces insulin to regulate glucose metabolism [t3]. Iodine's only known biological function in humans is the synthesis of thyroid hormones [t4, t6]. While thyroid hormones influence general metabolism, iodine itself is not a pancreatic secretion for cholesterol regulation. Therefore, only statement 2 is correct.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 6: Control and Coordination > Do You Know? > p. 110
2. [2] Science , class X (NCERT 2025 ed.) > Chapter 6: Control and Coordination > 6.3 HORMONES IN ANIMALS > p. 109
3. [3] https://www.ncbi.nlm.nih.gov/books/NBK613062/