Which group is incorrect?

Correct Answer: C

Rationale: The correct answer is C because epinephrine is not a steroid hormone. Steroids are synthesized from cholesterol and have a specific chemical structure, while epinephrine is a catecholamine. Cortisol, aldosterone, and testosterone are examples of steroid hormones, but epinephrine belongs to the class of catecholamines. Therefore, C is incorrect. A, B, and D are correct as they accurately list hormones produced by the anterior pituitary gland, posterior pituitary gland, and gonads respectively.

Correct Answer: C

Rationale: The correct answer is C: PTH. Parathyroid hormone (PTH) stimulates osteoclastic activity, leading to bone resorption. PTH plays a crucial role in regulating calcium levels in the blood. When calcium levels are low, PTH is released to stimulate the release of calcium from bones through osteoclast activity. A: Calcitonin actually inhibits osteoclastic activity, promoting bone formation. B: Androgen is a male sex hormone and does not directly influence bone resorption. D: Thyroxine is a thyroid hormone that regulates metabolism and does not directly affect bone resorption.

Correct Answer: B

Rationale: The correct answer is B because beta cells of the islets of Langerhans are specialized pancreatic cells that secrete insulin, a hormone crucial for regulating blood sugar levels. Insulin helps cells absorb glucose from the bloodstream, lowering blood sugar levels. Choice A is incorrect because the hormone-secreting cells of the adrenal cortex are called adrenal cortical cells, not beta cells. Choice C is incorrect as releasing hormones are typically secreted by the hypothalamus to stimulate the pituitary gland. Choice D is incorrect because steroids are primarily secreted by the adrenal cortex, not the beta cells of the islets of Langerhans.

Correct Answer: D

Rationale: The correct answer is D: Thyroid. The thyroid gland is located at the base of the throat, just below the Adam's apple. It is responsible for producing thyroid hormones that regulate metabolism and various bodily functions. The pituitary gland (A) is located in the brain, the pineal gland (B) is located in the brain as well, and the hypothalamus (C) is also in the brain. These glands play crucial roles in hormone regulation, but they are not located at the base of the throat like the thyroid gland.

Correct Answer: A

Rationale: The correct answer is A: Epinephrine and norepinephrine. These hormones are released by the adrenal glands during stressful situations to trigger the 'fight-or-flight' response. They increase heart rate, blood pressure, and energy production to prepare the body for action. Insulin and glucagon (B) regulate blood sugar levels. Estrogen and progesterone (C) are female sex hormones. Thyroxin and melatonin (D) are involved in metabolism and sleep regulation, respectively. Therefore, only A directly relates to the physiological response of 'fight-or-flight'.