MCAT Biology Practice Test 5: The Endocrine System

Home > MCAT Test > MCAT biology practice tests

Test Information

Question 15 questions

Time minutes

See All test questions

Take more free MCAT biology practice tests available from maintests.com.

1. Which of the following associations between a hormone and its category is INCORRECT?

  • A. Aldosterone—mineralocorticoid
  • B. Testosterone—cortical sex hormone
  • C. ADH—mineralocorticoid
  • D. Cortisone—glucocorticoid

2. Which of the following hormones directly stimulates a target tissue that is NOT an endocrine organ?

  • A. ACTH
  • B. TSH
  • C. LH
  • D. GH

3. Increased synthetic activity of the parathyroid glands would lead to:

  • A. an increase in renal calcium reabsorption.
  • B. a decrease in the rate of bone resorption.
  • C. a decrease in basal metabolic rate.
  • D. a decrease in blood glucose concentration.

4. Which of the following statements concerning growth hormone is NOT true?

  • A. Overproduction of growth hormone in adults results in acromegaly.
  • B. It promotes growth of bone and muscle.
  • C. It is produced by the hypothalamus but secreted by the pituitary.
  • D. A childhood deficiency in growth hormone results in dwarfism.

5. Iodine deficiency may result in:

  • A. galactorrhea.
  • B. cretinism.
  • C. gigantism.
  • D. hyperthyroidism.

6. A patient has a very high TSH level. Which of the following would NOT cause a high TSH level?

  • A. Autoimmune destruction of thyroid cells that produce T3 and T4.
  • B. A tumor in the hypothalamus that secretes high levels of TRH.
  • C. High levels of T4 from thyroid replacement medications.
  • D. Cancerous growth of parafollicular cells in the thyroid, destroying other cell types in the organ.

7. Which of the following hormones is NOT derived from cholesterol?

  • A. Aldosterone
  • B. Estrogen
  • C. Oxytocin
  • D. Progesterone

8. Which of the following is true regarding pancreatic somatostatin?

  • A. Its secretion is increased by low blood glucose.
  • B. It is always inhibitory.
  • C. It is regulated by cortisol levels.
  • D. It stimulates insulin and glucagon secretion.

9. Destruction of all β-cells in the pancreas would cause:

  • A. glucagon secretion to stop and a decrease in blood glucose concentration.
  • B. glucagon secretion to stop and an increase in blood glucose concentration.
  • C. insulin secretion to stop and an increase in blood glucose concentration.
  • D. insulin secretion to stop and a decrease in blood glucose concentration.

10. Which of the following is FALSE regarding aldosterone regulation?

  • A. Renin converts the plasma protein angiotensinogen to angiotensin I.
  • B. Angiotensin II stimulates the adrenal cortex to secrete aldosterone.
  • C. Angiotensin I is converted to angiotensin II by angiotensin-converting enzyme.
  • D. A decrease in blood oxygen concentrations stimulates renin production.

11. A scientist discovers a new hormone that is relatively large in size and triggers the conversion of ATP to cAMP. Which of the following best describes the type of hormone that was discovered?

  • A. Amino acid-derivative hormone
  • B. Peptide hormone
  • C. Steroid hormone
  • D. Tropic hormone

12. A patient presents with muscle weakness, slow movement, and calcium deposits in his tissues. A blood test reveals very low calcium levels in the blood. Administration of which the following would be an appropriate treatment for the blood test findings?

  • A. Calcitonin
  • B. Parathyroid hormone
  • C. Aldosterone
  • D. Thymosin

13. Oxytocin and antidiuretic hormone are:

  • A. peptide hormones produced and released by the pituitary.
  • B. steroid hormones produced and released by the pituitary.
  • C. peptide hormones produced by the hypothalamus and released by the pituitary.
  • D. steroid hormones produced by the hypothalamus and released by the pituitary.

14. Excessive levels of dopamine in the brain are associated with psychosis. Accordingly, many antipsychotic medications block dopamine receptors. Which of the following effects may be seen in an individual taking antipsychotics?

  • A. Increased secretion of growth hormone
  • B. Decreased secretion of growth hormone
  • C. Increased secretion of prolactin
  • D. Decreased secretion of prolactin

15. A genotypically female infant is born with ambiguous genitalia. Soon after birth, she suffers from hyponatremia, or low blood concentrations of sodium. Which endocrine organ is most likely to be affected?

  • A. Hypothalamus
  • B. Pituitary
  • C. Kidneys
  • D. Adrenal cortex