Free Chemical Coordination and Hormones MCQs with Answers

14 Chemical Coordination and Hormones MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.

14 questions · page 2 of 2

11. Steroid hormones act by

  • A. Binding cell surface receptors
  • B. Binding intracellular receptors
  • C. Opening ion channels
  • D. Activating second messengers

Explanation: Steroid hormones (lipid-soluble) diffuse through membranes and bind intracellular receptors that regulate gene transcription.

Correct answer: Binding intracellular receptors

12. Type 1 diabetes is caused by

  • A. Insulin resistance
  • B. Autoimmune destruction of beta cells
  • C. Excess insulin
  • D. Pituitary tumor

Explanation: Type 1 diabetes is an autoimmune disease where beta cells are destroyed, requiring insulin injections.

Correct answer: Autoimmune destruction of beta cells

13. Calcitonin lowers blood calcium by

  • A. Increasing bone resorption
  • B. Decreasing bone resorption
  • C. Increasing calcium absorption
  • D. Decreasing calcium excretion

Explanation: Calcitonin from the thyroid inhibits osteoclasts, decreasing bone resorption and lowering blood calcium.

Correct answer: Decreasing bone resorption

14. The stress hormone adrenaline causes all EXCEPT

  • A. Increased heart rate
  • B. Bronchodilation
  • C. Glycogenolysis
  • D. Decreased blood pressure

Explanation: Adrenaline increases (not decreases) blood pressure through vasoconstriction and increased cardiac output.

Correct answer: Decreased blood pressure