Which of the following best defines hormone specificity?

• A. The production of hormones exclusively by endocrine glands
• B. The rapid breakdown of hormones in the bloodstream
• C. The transport of hormones through the circulatory system
• D. The ability of a hormone to bind only to its specific receptor on target cells

Answer: (D)

Verified step by step guidance

1. Understand the concept of hormone specificity: Hormone specificity refers to the ability of a hormone to bind only to its specific receptor on target cells. This ensures that hormones exert their effects only on the cells that have the appropriate receptor.
2. Recall the role of receptors: Hormones interact with receptors that are highly specific to their molecular structure. These receptors are typically proteins located on the surface or inside target cells.
3. Consider the mechanism of hormone action: When a hormone binds to its receptor, it triggers a cascade of cellular responses. This specificity prevents hormones from affecting non-target cells, ensuring precise regulation of physiological processes.
4. Eliminate incorrect options: Review the other choices provided in the problem. For example, while hormones are transported through the circulatory system, this does not define specificity. Similarly, hormone production by endocrine glands and their breakdown in the bloodstream are unrelated to the concept of specificity.
5. Conclude with the correct definition: The correct answer is that hormone specificity refers to the ability of a hormone to bind only to its specific receptor on target cells, ensuring targeted and regulated biological effects.