What is the half-life of the isotope?

Correct Answer: A

Rationale: The correct answer is A (80s) because the half-life of an isotope is the time taken for half of the radioactive nuclei to decay. In this case, it takes 80 seconds for half of the nuclei to decay. The other choices (B, C, D) are incorrect as they do not represent the correct time interval required for half of the nuclei to decay.

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.

Correct Answer: A

Rationale: The correct answer is A: calcium. PTH (parathyroid hormone) activates vitamin D, which in turn helps in the absorption of calcium in the intestines. This is crucial for maintaining bone health and normal calcium levels in the blood. Vitamin C (Choice B) is not directly related to PTH or vitamin D in calcium absorption. Iron (Choice C) absorption is influenced by factors other than PTH and vitamin D. Phosphate (Choice D) absorption is primarily regulated by fibroblast growth factor 23 and not by PTH or vitamin D. Thus, the correct answer is A as it directly corresponds to the role of PTH and vitamin D in calcium absorption.