Answer:
a. True
Step-by-step explanation:
Hormones are signaling molecules that are produced by endocrine glands. The role of hormones is to control physiology or behavior. They can be classified into three categories:
Peptide hormones – derived from a chain of amino acids
Amino acid or fatty acid hormones – derived from an amino acid or lipids respectively
Steroids – derived from cholesterol
Thyroid hormones are considered steroids. They are produced by the thyroid gland and are responsible for regulating metabolism.