Which colour change is observed when water is added to anhydrous cobalt(II) chloride?

Correct Answer: B

Rationale: The correct answer is B: blue to pink. Anhydrous cobalt(II) chloride is blue, and when water is added, it forms a pink hexahydrate complex. This color change occurs because water molecules replace the chloride ions in the crystal lattice, resulting in the formation of the pink complex. Choice A (blue to white) is incorrect because the addition of water does not change the color to white. Choice C (white to blue) is incorrect as anhydrous cobalt(II) chloride is blue to begin with. Choice D (pink to blue) is incorrect as the addition of water causes the color change from blue to pink, not the other way around.

Correct Answer: B

Rationale: The correct answer is B: hypothalamus. The hypothalamus is considered a neuroendocrine organ because it produces and releases hormones that regulate the pituitary gland's hormonal secretion. It acts as a bridge between the nervous system and the endocrine system, controlling various physiological processes. The pituitary gland (choice A) is a master endocrine gland, not a neuroendocrine organ. The pancreas (choice C) is an exocrine and endocrine gland involved in blood sugar regulation. The adrenal cortex (choice D) is part of the adrenal glands responsible for producing steroid hormones, not considered a neuroendocrine organ.

Correct Answer: A

Rationale: The correct answer is A: adipose tissue. Resistin is primarily produced by adipose tissue and is known to antagonize the action of insulin, leading to insulin resistance. Adipose tissue is a major source of various hormones, including resistin. Option B: heart, and Option C: liver, are not the correct answers because resistin is not known to be produced by these organs. Option D: hypothalamus, is also not the correct answer as resistin is not produced by the hypothalamus. In summary, the correct answer is A because resistin is primarily produced by adipose tissue, which plays a significant role in insulin resistance.

Correct Answer: B

Rationale: The correct answer is B: Renal artery. The inferior suprarenal artery arises from the renal artery, which supplies blood to the adrenal gland. This is anatomically accurate as the adrenal gland is located superior to the kidneys. The other choices (A: Abdominal aorta, C: Inferior phrenic artery, D: Splenic artery) do not supply blood directly to the adrenal gland. The abdominal aorta gives rise to the renal artery, the inferior phrenic artery supplies blood to the diaphragm, and the splenic artery provides blood to the spleen. Therefore, they are not the correct origin of the inferior suprarenal artery.

Correct Answer: a

Rationale: The correct answer is A: Isometric contraction. In isometric contraction, the muscle contracts but there is no movement at the joint. In this scenario, Adonis's biceps brachii contract but the weight is not moved, indicating an isometric contraction. In concentric contraction (B), the muscle shortens to move the weight upward. In eccentric contraction (C), the muscle lengthens while under tension, controlling the descent of the weight. Incomplete tetanus (D) refers to a state where muscle fibers are stimulated rapidly but not at the maximum rate to produce sustained contractions.